You got a 60 gallon cube no need for dwarfs get some real south Americans. 
So what species would work together. Not interested in breeding. 3-4 tanks for me. Not 34. lol
I'm not sure what real SA's he's talking about for your cube - you have lots of nice volume but not a lot of length to get territories, so I'd be hesitant about anything much bigger than the keyhole cichlids recommended above.
Nannacara anomala (golden dwarf cichlid) are nice and seem to mix OK with angels and/or rams but not apistos (at least not apisto agassizi or apisto...I forget the other species I had that didn't like the nannacara either.
Angels and rams (either pair of German Blue or pair/trio of Bolivian) have mixed well for me in a 50 long and a 75, as well as briefly in a 29 high (30x12x18) which is closer to the dimensions of your tank but yours is deeper front to back. Or you could do a single of each species. The reason for getting a pair is that angels will often kill each other if you get two of the same gender in a confined space (under 4', in my opinion), and rams will chase each other around though not typically kill if you have two males or two females. On the other hand, a single angel may nip but shouldn't team up and take out other teammates, so that might be a better option to get a single.
You may already know this. These are some options if you're talking strictly cichlids.
If you expand to catfish and tetras, I like SA bumblebee catfish and some of the smaller plecos like bristlenose or L201/inspector/contradens, etc.
Many tetras will get eaten as the angels mature but black neon tetras seem to do well and are much hardier than their blue/red cousins. Also lemon tetras, rummynose tetras, and similar are higher-bodied than neons so have a better chance in with angels.
You can do a group or two of livebearers like guppies..but especially if small the angel may pick off a few.