I'd say roughly 10gal/Angel. So that would be 4.
If you have good external filtration, I would go with 5.
You could have a few bottom dwellers, some Cory's and a smaller Pleco.
And maybe a shoal of medium tetras. Say Bleeding Hearts.
What types of Angels?
Well that comes down to perosnal preference.
Don't rush out and buy the first ones you see. Take your time. Shop around, and see which ones you like.
I have the Platinums and Smokey Leapards in my tank which are my faves. Koi are also very nice.