Yes that stocking would be fine, I'd say go for like 20 congos max. The congos get big.
About the green terror and angels, I would probably not try it, just because the GT may get aggressive with them and rip their trailing fins. I think angels should really be kept with less aggressive, smaller, non-nippy fish. You could probably do some other smaller SA cichlids with the GT's, cupido comes to mind. But it would be dependent on how your GT's behaved.
i meant:
Angelfish x20
Male Cockatoo Dwarf Cichlid x1
Female Cockatoo Dwarf Cichlid x3
Male Bristlenose Pleco x1
Female Bristlenose Pleco x2
