Looks like your doing fine. Dont be affraid to make mistakes, they can be costly but they can also be a huge help in the learning curve.
Here are a few tips for you. Since you already have glass tops you can simply add another light in the front section of the bow. Measure first and then get one that fits, for width measure your existing light.
For a cheap substrate you can use laterite and then cap it with pool filter sand. (just research this topic first due to possible algea blooms)
you can use the cheap fertilizers from the plant stores. Reasearch the EI fertilization method and that will lead you into everything you never wanted to know about fertilizers.
Dont worry about plants just yet. Let the tank cycle for a couple of weeks and get a test kit. When your ammonia and nitrites hit 0 and your nitrates are under 40ppm you are ready for fish. This may take some time. After having fish wait till algea happens then get an algea crew. After you ahve an agea crew your ready for plants. If you go and stick plants in a substrate with no fertilizer, I.E. Poop, then without good fertilization they wont ahve any food.
There are several product on the market to help speed up the cycling process or you can uSe an existing cycled sponge filter or substrate to speed up the process.
Expect to learn about DIY CO2 or spend a considerable amount of money on the big dog top of line pressurized systems.
Well thats enough for now. Hope you enjoy it. Look at like a bunch of ten gallons only difference is if one crashes well you know...
(Pay it forward)
P.S. For the old sump intake pipe you can use it as the new intake to the eheim canister filter your using just reduce the size to a barb that fits the eheim tube. Then you can get ride of the green eheim intake and only have two tubes again.