i also have both and they do fine. I wouldnt put 3-4 angels in it thou as they get big and are territorial. I would only do a pair of each. as far as hardiness.... i think they are my ph is kinda high for them but i was told instead of trying to lower that so long as the ph stayed consistant they would adjust, its when the levels change constatly they stress. now as for the schooling fish... i have von rio tetras in mine and they look very nice together. Von rios are of the smaller variety and it is possible that they will be eaten but from what i understand if you grow them up together and feed them well then its less likely to happen. But a nice school of tetras (not neons) would look nice.
These guys can be treated like Discus and go for the 1 fish per 10 gallon rule. Just like Discus, if you get a pair the pair can get aggressive and fish will need to be moved around. Both tank bred Ram and Angel will do fine in a wide range of water parameters. My Ram breed regularly in a high Ph.
BubbleBaby,
The height of the tank is a good thing, the Rams won't mind and the Angel will prefer it. Angels need a 18' minimum anyways.
I think the pair should be okay, try to get M/F. I got a M+F and they just paired up. Might have been lucky, don't know.
Both the Ram and Angels will do well in your soft water. They prefer these parameters but aren't limited to them. You will find that they are going to be very sturdy in those parameters. Just keep up on your 25-30% weekly water changes.
A few other tank mates off the top of my head:
Bigger sized (peaceful) Tetras (small tetras like Neons and Cardinals will probably get eaten)
Small sized Pleco
Corydora (higher temp. species do better)
Gourami (stay away from bigger species like kissing gourami)
BTW, Keep the temperature anywhere from 80-84F.