The price for used one is about half of the price of a new one here on local Craigslist (that's good for me). Therefore, I want to pick up an used PS Vita. I want homebrew so what should I, so: What model/serial of PS Vita is most desirable (please give 2nd, 3rd place too if possible)? What firmware or other requirements should I look at? What should I check to see whether the PS Vita is fully functional (what are some common issues?! For example: joystick on PSP...) Please be patient with me because I know nothing whatsoever about PS Vita!