I do be thinkin that this tank be lookin epic! When the plants fill in it will look awesome, I can feel it! And the fish won't mind a little less space, so long as the filtrations good and the fish aren't giants. Good Job!
filtration better be good! I am running an FX5 on this tank! lol. I also have some pothos clippings and one of those mini bamboo plants hanging out on the back of the tank for a little nitrate scrubbing and to soak up extra nutrients. They seem to like my fish water.
I've been thinking about adding a GBR pair or bolivian pair. I know this would probably destroy my RCS colony though so I'm not really sure if I am set on doing this, as I have made a decent amount of money selling my extra shrimp locally to other people.
If you're still looking for a taller plant, I've got a rec.
Aponogeton Ulvaceus. I got this one as a bulb on 12/10/10. It's now about 3 feet, but my tank is only 21". My fish love it, especially my platy fry. Here are some pics of the smooshed plant.