Thanks so much. I'll be looking at angelfish with rams then I think. I can indeed keep different types of rams together, yes?
IMO it would depend on if you have a pair or not. Bolivians and German Blue Rams will both spawn on an open, flat surface, so if you have at least one pair, all of the others are going to be bullied a bit. I think some have kept same-sex Rams to avoid this, but I'm pretty sure I have 2 male Bolivians right now and they are NOT the best of friends. Bolivian Rams are quite hard to sex when they are juvenile, so it can be a bit of a toss up. I've gotten pretty good at sexing the GBRs (at least in person), but can't seem to keep them alive in my tank.
If you do get bottom dwellers and the Rams spawn, they will probably be beaten up a bit. Also, if you want Cories I think you have to stick with Sterbai or Adolf as they can tolerate warmer temps (both Angels and Rams like their water warm and many Cories like their water a bit cooler). Cories do like to be in groups, so you'd probably want at least 4 of those. I think Cories prefer a mature tank, but I don't remember for sure. While I had my Ram pair I had a BN Pleco and he got along just fine.
What about this:
4 - 6 Angels
2 Rams
4 - 6 Cories
You may also want to look at a small group of dither fish, but large enough that the Angels won't eat them.
I can't remember what kind of substrate you are going to have (I think another post said sand?) but the Rams and Cories will appreciate sand.
Hope this helps!