Okay, so, you will NEED a pair of German Blue Ram, otherwise the tank will never work
But really, with the stocking you have I would do:
25 MALE guppies (unless you want a tank filled with trillions of tiny ugly guppies you can't get rid of).
15 Hatchets (tight fitting hood recommended!)
20 Neon Rainbowfish (Very pretty, 3in long tops, awesome in larger numbers)
2 BN Plecos (a pair would do best, plus possible breeding and selling = profit!)
2 German Blue Rams (same as BN Plecos)
7 Flame Dwarf Gouramis (one of the few that do better in groups then alone, provided more females then males)
25 Neon Tetras (great mid-level fish for the beginner and the experienced alike!)
10-15 Penguin Tetras (larger mid-level fish, very vivid coloration!)
5 Otos (to control algae and look cute doing it!)
I do believe that stocking remains under the 3in max rule and that it would work, though tweaking may be needed to lower total stocking or level stocking. I would also have corys in there, at least 20 of them, but you (for some reason) don't like them (SHUN THE NON-BELIEVER!) so I left them off.
Good luck with your new tank!