I would use a canister filter of some kind. As far as the best, I use a Rena Filstar. It works great and is pretty quiet. I am not a fan of Fluvals, they are difficult to service, and the ceramic shaft is easily breakable. Yes, use a protein skimmer. That will have to hang on the back though. There are many good small protein skimmers; Red Sea makes one called the prizm. and CPR makes a nice one called a Bak Pak. The only problem with the Bak Pak is they (used to at least) use a rio pump, which are terrible to say the least. I suppose you could plumb a U.V. sterilizer into the return on your canister filter. It would be a little expensive, but your water would sure stay clear. Have Fun,
Ryan