PSP Battery Service Tool Or PSP MAX Power TOOL SLIM?

so i was wondering which product i should buy. The PSP Battery Service Tool Or PSP MAX Power TOOL SLIM? I have the God of War Bundle pack so its a psp 2001 (which i think is slim?)

i was at a forum (lost the page/bookmark) the admin told me he bought the PSP Battery Service Tool and said i should to so i wont have to mod much.

but i was wondering which one i should get, i was to do custom firmware and run diff apps and like i said, i was told the best way to do so is using the service bat packs.

so can anyone tell me which one i should get?

here are the links. I'll throw all 3 "tools" i found. email me or reply to this and please tell me which one is better or both

( PSP Battery Service Tool & PSP MAX Power TOOL SLIM)

thanks alot

oh and the price dosnt matter...
(This is the one the admin from another forum told me to get)
http://us.codejunkies.com/Products/PSP-Battery-Service-Tool__EF000530.aspx

(i think this is the same but its "only" for the slim)
http://us.codejunkies.com/Products/PSP-MAX-Power-TOOL-SLIM__EF000513.aspx

(this one is the one for the "original" psp)

http://us.codejunkies.com/Products/PSP-MAX-Power-TOOL__EF000536.aspx

thanks again, i just dont want to blindly want to order both when the 1st one dose the same as 2 and 3 but is a better deal...you know...