well i would ask him to install a cfw (unless you wanted to do it), now theres a few different firmwares out there, split up into 2 groups (CEX and DEX) me personally, i would recommend for you to go onto a cex firmware since its noob friendly and dex has alot more option that you dont need, so theres a few cex firmwares, but i would recommend rogero 4.46 using the ARCH spoofer (
You must login or register to view this content.) but you should be able to install that yourself, the seller SHOULD know what these firmwares are,
now some useful homebrews that you should get installed-
multiman
psninja
psnpatch
and ccapi
so just tell him you want it to be on a rogero 4.46 cex firmware with multiman, psninja, psnpatch and ccapi installed