surge protectors

Hi Anyone who knows surge protectors!
Does anyone have any advice on surge protectors? We want one that is reliably and will protect us against most of the surges that might happen at a campground. What specifications should we be looking for. We were talking to some sales people at camping stores and we got different advice. We are not sure they know any more then we do. Here are the specifications of one surge protector we were offered at one store, the only one they had. Voltage: 120V AC; Current: 30A Max; Watts: 3600W Max; Surge Modes: Triple (L-N, L-G, N-G); Total Surge Capacity: 210 Joules; Surge Nominal Voltage: 208 Volts; Max Spike Current: 6500 A; Trip Time: <25ms; Trip Current: <10ma; Fault Indication: Mechanical; Power Available Indication: Visual (green LED). What do you think of the specification? Are they sufficient or should we go for higher spec, and higher in which ones? What about the hard wired surge protectors? Should we get 30 Amp or 50 Amp? Thanks R Chaisson