expansion valve for CPU cooler

What type of expansion valve should I use on a CPU cooler (I'm thinking CPEV)? The compressor is about 1/6hp (Embraco EMI60HER) and it uses R134a. I expect about 40C condensing temperature. The load can be anywhere from almost none to 150w. I plan to be able to use my unit for many different CPUs so a captube alone is not a good solution. BTW, I live in the Sugar Land, TX area and the local stores I know of are Johnstone, ACR Supply, and Grainger. I'd prefer not to web order as I want to be able to actually hold and look at the part before buying it.