I haven't had rainbow fish before but I feel like they might be a bit active for a 4 foot tank. Size wise I personally wouldn't have a problem with putting the in a 75. I wouldn't have a problem with putting all the fish you listed together except for the pictus for their active and maybe the rainbow fish but I run my tanks at a heavier stocking. Let's ask for another opinion.
Heytlindsey what are your thoughts?
I'm one of those Geographically correct anal types, that feel Asian gouramis and Australian (New Guinian) rainbows are out of place in a primarily South American tank.I'd go for the EBAs over your other options, I think gourami would be out of place in the mix. Also 1 large school of tetras is more appealing to me than 2 small ones but that's just personal preference. Maybe as others have suggested have a school of tetras and hatchets. Have you looked at Columbia tetras? A cool looking larger tetra which would suit your tank.
Overall I would try to stick to South American as much as possible so wouldn't go for the rainbows or gourami. I love pictus cats but as has been said they would make too much of a ruckus for the rams.

