There is no "RCA out" just XLR, RCA and 1/4" TRS inputs. Long & McQuade sell midway decent cables themselves. You could probably hack an RCA cable to work like you mentioned. Probably better to get some decent cables for them though, and go XLR if you can.
then why did you say that?
Also where can i buy singular rca cables
Also, most RCA cables come 'joined' together, but they can easily be peeled apart (which I did)
As for locations, Long&Mcquade has them, so does 'The Source', Best Buy, Futureshop, almost any electronics/music hardware store has them, as they are a pretty standard connection.