Advice: dont listen to anything wal-mart employees have to tell you.
same goes for petco,petsmart and the like.
In fact many so called "mom and pop" fish stores are just in it for the money nowadays as well,they cant afford not to be.
The best place to get fish info is from a fish forum.
Fish Kept: malawis,right now:
electric yellows and blues
alot of eureka peacocks (my favorite)