The four foot tank should be plenty of territory for both the Rams and Apisto's, just make sure there are good nesting sights on both ends of the tank.
A really good set up is a 55 gal set up with about 3 pairs of rams/apistos and a group of discus and maybe some cardinal tetras, so remember, the bigger the better
my discus wont be in the 55G forever but they do intend to have them together for at least 3-4 months my discus are 3" currently with 3 of them these fish are fine int he 29G at least getting along wise of course bigger is ALWAYS better...but i will be doing more research on this my LFS has some golden rams angain also has long finned, but the thing s the apistos have been drawing my attention heavily...i will always love rams though!!