A pair of Altums, a HUGE school of Harlequin Rasboras, Odessa barbs (smaller school), a big school of Corydoras (green, schwartz, trilineatus - whatever you can find several of), and, of course, plants. It's a tall tank, so you could do tall crypts or vals in the background, then work your way down to some glosso or chainswords in the front corners.
(got budget for a few 54W T5s or a couple of 96W bright kits and a hood and more CO2?)
I'd also be tempted to get some tiny sevrums, GTs, a JD, couple of flag fish - then watch 'em all grow out among several well rooted, large plants - vals, swords, moss on DW. That would be a really long term committment...