I need to replace existing outlets with GFCI outlets in my kitchen and bath. My question is on the type of outlet to purchase. The breakers are 20A and the cable has 12ga conductors (I think). Based on this I'm thinking that I need 20A rated outlets, but I'm having trouble finding them at the big box stores. So.....if I am correct about the wire gauge am I comitted to 20A outlets? Can I put a 15A outlet in this circuit.