On the RO system, I would suggest against it unless you know you need it. (b/c specialty fish, super high pH out of tap, etc.)
I got a cheap RO system 3 years ago because I wanted to do Apistos and read from several sources that they need the super low pH, soft water, etc etc. Used it for the first year 50/50 RO and tap (tap was softish, 7.2 pH), but noticed the plants in the non-RO tanks were doing a lot better. The plants weren't anything special -- Crypts, mosses, Hygro, Swords, etc.
But the non RO water made the plants in the RO water look unhealthy in comparison. Lighter colors, less growth, etc. I wouldn't have noticed the difference had I not had them next to eachother. But looking at them next to each other there was noticable difference.
I started cutting back my RO ratio until I wasn't using any RO. Fish, including Apistos, never noticed and the plants started doing a lot better. Actually I think some of my fish, like my barbs, did better.
I still have the RO unit but haven't used it in 2 years, and wont in the forseeable future. If I start getting Apisto eggs that dont hatch or something like that I might go back to it. As is, I consider it a bit of a waste, considering for the same price I could have bought all the RO water I ever needed (none thus far) from the LFS and had money in my pocket.
Pictures. Sorry not better resolution, taken with phone. Look at the Crypts
First Pic is RO tank. Notice the thin leaves, long stalks, lighter color.
Second Pic is another RO tank. Crypts in front left. Thin leaves, but better color.
Third pic it non-RO tank. Crypts on right. Broad, long leaves, deep green with some red.
Fouth pic is all 4 tanks next to eachother. First pic is top right tank, second is top left, third is bottom left.
All crypts are same species. Actually, the crypts in the 2nd and 3rd pics are from tiny bits that from the crypts in the first tank that I split off or split off naturally. As you can see the baby plants quickly (2-3 months) caught up and surpassed the mother plant without RO.
As a sidenote I found that the crypts (and my plants generally) also did a lot better in Flourite (2nd and 3rd pic) rather than Ecocomplete (1st pic). All tanks had same lights, temp, and fert (not much). Only other difference is that nonRO (3rd pic tank) was a 10 gal, not a 20 (like 1&2), but they are the same height so I think the effect on light would be non-material.
[Edit: Don't use the other plants in the 1st tank pic as reference. They were brand new plants, just planted. The swords ended up dying back and the Hygro got leggy. Also the sword on the top left tank slowly shrunk over time, and I got a runner from it that I planted in the bottom left (non-RO) tank that outgrew it.]
Bottomline, I found RO to hurt me more than help.