catfish newbie :)

Im guessing by sucking catfish you meen pleco, by peppered catfish you meen paletus cory. The albino catfish needs more though because you could have either an albino cory (which is hopfully what you have) or possable a albino channel catfish which you should take back right away if thats the case ( it will eat everything else). Also it would help a TON if you posted you tank specs ( size, water chemistry etc...). Clown loaches are great fish but they grow large (10-12") and need to be kept in at least a group of 3. They also require a large amount of swimming room and a strong current ideally.
Hope that helps. Posting back with more info will help us help you also.