Heres my experience of Rams. I have one large Male Dutch Ram & one Bolivian Juvenile (as of yet unsure of sex, although looks to be a male due to colour definitions appearing)
My Rams are kept with a lot of other fish in a large tank, mostly small fish, but include various gouramis, various tetras, a few loaches, some catfish and a few other fish.
I have watched their behaviour for a long time and when i first put them in the tank my Red Tailed Black Shark took an instant disliking to them (however im lucky enough to have more than one decent sized tank and therefore promtly removed the shark into one of my other tanks).
Since then they have been quite happy in the tank and are fine together. I have seen the larger one on very rare occasions chase the red honey gouramis (normally at feeding time) but hasnt attacked them (and believe me the rams are super quick in comparison to any gouramis)
This is just my example of Rams behaviour, but believe me it does depend on the individual fish, there are no set rules as far as rams are concerned in my opinion as ive heard and read so many different stories about them...
Best plan is to just give it a try, make sure your lfs will take the fish back off your hands if they dont get on in your tank (unless you have more than one tank and can segregate certain fish)
Good Luck