What andysgirl said is true but I will go out on a limb and say most people with that small of a tank don't even use a protein skimmer. If you do regular water changes, something like 15% once a week, and don't overfeed your tank you should be fine w/o one IMO. As far as the testkits I would recommend the API Saltwater Master Kit for starting out. It comes with Nitrate, Nitrite, PH, and Ammonia tests in liquid form. I have had good results with them and they are cheap. You can get Calcium, Alkalinity, and Magnesium tests from better, more expensive, company's like Salifert later on when you have corals.