bettas can be kept in a community and kept happy, but it depends on two things, one of which you can control and one you can't:
1. the fish you keep with your betta. Like you said, slower non-fin-nipping fish, also, you don't want brightly coloured fish or fish with long flowing fins.
2. The betta's temperment. This is the one you can't control. Some bettas are pretty laid back, others won't tolerate any kind of tankmate and will try and attack it.
If you are going to try a betta in a community tank it's always best to have a small spare tank (2.5 gallons and up) which you can move the betta to if it doesn't work out.
So it is possible, but there are disadvantages: you will be very limited in what other fish you can keep and it may not work even if you do choose the right tankmates.
I've not kept a betta in a community tank, so I'll leave species suggestions for tankmates for someone else.