I agree that a 5 gallon is WAY too small for a male betta and 2 gouramis. You're just asking for fish murder with that set up. A 5 gallon would be great for a betta by himself. At most, you could probably add a few glass or ghost shrimp, or maybe 2 ottos, IF you have sufficient GA growth. 2 dwarf corys would probably be better than ottos.

I had a GREAT community tank running for about 2 years. In a 10 gallon tank, I had:
5 head-light-tail-light tetras
2 panda corys
3-6 ghost shrimp at various times... sometimes they got eaten, sometimes they lived for a while.
1 male betta (gold veil-tail)
MANY plants, most notabley java ferns, java moss and some micro-swords.

I used a Whisper 5-10 gallon power filter, fitted with a sponge on the outlet to dampen the current for the betta, which worked well.

The betta I had in the tank was previously living in an unfiltered 2 gallon with a java fern. He was fine, but when I put him in the 10 gallon, he really came to life!!!! His colors got much brighter, he was much more active and entertaining, and just seemed happier. After 2 years in the community tank, he died of dropsy (he was old, too... 3 yrs.)

The 10 gallon was great for 3 big reasons...
1) it is easier to HEAT a 10 gallon than a 2 gallon, and in the warm aquarium water, the betta just seemed so happy.
2) the filter with reduced flow AND the heavily planted environment made for great water quality. Although bettas are very hearty and can tolerate living in crappy conditions, they are at the top of their condition in good, clean, oxygenated water.
3) the fish were all of a similar size, none of the others even remotely resembled bettas, the tetras were not nippy, and everyone (except for the shrimp!) was fast enough to get away.

After my betta died, I adopted 4 male guppies from an over-crowded tank at a friend's house, and therefore, I can't mix a betta with them. A betta WILL kill a guppy!!!!!

I couldn't resist bettas though, so I now also have an Eclipse system 3 (3 gallon) with a blue male betta. It is planted, and he seems pretty happy