I have a 75 gal setup kinda like the one you envisioning. It may be a little over stocked but my stock is as follows. 5 angels, 9 black skirt tetras 2 cory cats, one emperor tetra, 2 siamese algae eaters, 2 male swordtails, and an african butterfly fish. Doing weekly water changes all seems good, i did have neons but the angels eventually saw them as food. Leopard danios also got picked and had to be moved out. I would suggest at least five angels, a large school of med sized tetras, couple of cories and possibly a pair of rams. I would add all the angels at one time i noticed some aggression when i introduced my last two even only three weeks later.