Billy, check out the depth of that tank against the guy who is standing in front of it. Now imagine yourself trying to prune/maintain a tank that deep, especially with only two foot of head room between the top and the ceiling.
A tank that high will need a ton of CF or MH lighting. This will also cause the need for CO2 injection. With that and good fertilization the growth is going to necessitate a lot of attention.
The point is that I think you should research this a lot more before getting in 'over your head' so to speak.
Tom Barr is one of the most well known and most influential aquarist/scientists around and had a huge amount of know-how and resources when he built that tank. Not to mention years of experience with planted tanks and all involved with them. I would suggest running your ideas by him and getting his advice before going ahead with the project.
Len