So is something like this what I'm looking for as a power supply?

http://www.ebay.com/sch/Business-Industrial-/12576/i.html?_nkw=variable%20power%20supply%20dc&_fln=1&_ssov=1&_trksid=p3286.c0.m1539&_mPrRngCbx=1&_udlo=&_udhi=50.00

Variable voltage is a must I take it. Also is 2Amps enough? Sounds like a lot but I know nothing???

Thanks!