[The Dude1]

I have a 2215 on my 75 gallon and it's pretty much useless other than as a filter for the reactor. I added an AC110 and a big dual circulation pump. With a reactor and an inline heater I would go no smaller than a 2217 if you want it to actually filter and have some flow.
If it were me.... I would do a big group or two of small active shoaling / schooling fish... I love Celebes and Gertrude Rainbows. I saw Blue Emperor Tetras for the first time today and they are amazing... I've got a school of Rummynose which are also awesome. You would have room for a group of Corys for sure I would think. I would do 8 of some of the smaller ones.. pandas or maybe 6 of the bigger ones like Juli or Sterbai. I really like heavily stocked tanks... and I can't stick to a plan... there are just too many awesome fish and some fish I just have not had luck with... like Neons and Cardinals... but they are really pretty. I hear green Neons group better.

 

[The Dude1]

If you go with warmer water fish like cardinals and Sterbai Corys you could do electric blue rams... they look amazing. Very attention grabbing. I have cooler water fish other than the group of cardinals so I couldn't do them. I will eventually. That crazy bright electric blue color with bright red eyes. I spent 30 minutes staring at them today trying to figure out where I could keep them if I rearranged my tanks. Just couldn't do it. All of my tanks are moderately to heavily stocked. The moderately stocked ones aren't fully stocked yet. I visit the LFS weekly or biweekly getting my stocking where I want it. Fortunately my LFS is top notch and will get me pretty much anything I want at very good prices. They focus on the more rare species. They keep the main stays like cardinals, Neons, and Rummynose, but also alot of the plant friendly dwarf cichlids, Rainbows of all types, CPD's, loaches, lots of cool stuff. New stuff each week. Have you checked out panda garra and panda loaches? Really cool really good algae eaters with really cool personality and interactions.

 

[The Dude1]

Good choice on the regulator set up. Do it once, do it right, and never worry about it again. I paid to have mine built exactly how I wanted by someone that's built a bunch of them.
That sucks about the shipping... Ive been there... Things should ship out the next business day or AT WORST the following day. I had an IPhone 8 plus that I waited on for 16 days... finally I called and asked what's up and it was lost. They told my wife she had to wait 30 days for the investigation... I called back and said no I don't. I don't care where it is. I don't want it. Cancel it. You should have shipped it overnight or at least Priority. $1000 phone!! Ended up with $100 in bill credits and picked one up locally at a store a few hours later. I can tell you most people on here are top notch with shipping and packages. I planned on getting some huge pieces of driftwood for my 265 from the same person... but not if you don't have it 13 days later.
I personally don't think that those buffered substrates are all that important unless you have super soft water fish or shrimps. Pool filter sand and black sand (I get it from Petco) have grown everything I have every wanted. I will drop an osmocote tab under root feeders. With a quality C02 system and dry ferts you aren't going to have any problems.
This is going to be a killer set up. All first rate stuff. If you have any more plant purchases I can tell you that Herns and Burr are first rate guys... Strungout... and another guy that sells Buces 5 for like $35... they are usually my go to. I'm sure there are many others, but I check with them first if I want something.
Totally up in the air about fish or are you narrowing it down any?

 

[The Dude1]

Ya you will need at least 2 more similar size pieces to make anything out of that. Oh well... If that's the worst that happens you're doing pretty good!! Sick looking regulator.

As to the top... could look really good either way... but you wouldn't see the nice finish of the granite. Concrete can look REALLY good if you know what you're doing.

 

[The Dude1]

Still waiting on the light. Was supposed to be here today according to tracking but when DHL gets involved...all bets are off. I wanted to use it over my 11g I scaped today to upgrade the 7g I have shrimp in now...then on Christmas I'm supposed to get a Finnex 24/7 for the 11g and the sbreef will get put away to wait for the 32g setup.

DHL is awful... I find myself calling Amazon or sellers and asking specifically about shipping methods now. It it's something I want / need I will pretty much demand Priority. What's funny is it's normally less than $1 more... DHL and UPS are atrocious.. I can't count the number of times they have lost things... like my IPhone 8 plus just a couple months ago..
I would call the seller to be sure, but if it were me I'd buy another and send that back when / if it ever arrives. Or refuse it. You were told it would ship right out... 2 - 3 days... that's not an acceptable practice. They should have contacted you if it was an honest mistake. I only expect that people do the minimum... but most don't do that. I'm very discerning about who gets my business / money now. When I was buying 30k cars no one really cared... 100k cars and some of the other expensive stuff I can afford now... I will take my business elsewhere if I see or hear of shady crap like that. I had to take my Z06 in for service the other day (months ago) so I took it to the dealership I have purchased 10+ vehicle from. Their new service manager treated me like a moron... like I was beneath him... it was unreal... the manager called me 3 days later to inquire about the new ZL1 I was considering so my wife could have the Z06 full time. I was very satisfied in telling him I'd take my 85k purchase to another dealer and would not return for any reason due to their obvious values in placing someone like that in charge of service. I did check out a new Hellcat Saturday and I think I'm going to pick it up when we get back from Christmas vacation. They introduced me to everyone in the dealership from the owner, to the GM, to the Head Service Manager.. They even took the car out of the showroom so I could hear it. No test drives on 707hp cars... even when you pull up in a faster more expensive 650hp car I guess.