Nice parts so far. For tubing, that's all on personal preference; either 3/8" or 1/2" is perfectly fine, just choose any OD (outer diameter) and you're set; as for the brand, go for Masterkleer (avoid ClearFlex, it tends to cloud up) if you're on a budget, or Tygon if you have lots of tight bends. After that, pick fittings/barbs that match the tubing size (and make sure they're G1/4"; I recommend Bitspower compression fittings), and then fans for the radiator (see here for recommendations). If you want a reservoir, the Swiftech MicroRES is an excellent option that will fit just about anywhere. Hope this all helps.