Should I buy a normal PSP battery or a Pandora battery?

Ok so I just bought an UNLOCKED PSP off ebay and the person who sold it to me said it has already been hacked with Custom Firmware 6.20 Pro-B7. I've never owned a PSP and I'm kinda new to the whole custom firmware thing, but I always heard that if you're hacking your PSP, you'd need a better battery for more power to ensure that your PSP won't brick (Pandora battery). I asked the person who sold me the PSP if I needed it just in case, and he replied that I just needed a normal battery and everything should work fine.

Should I buy a Pandora battery anyways just for good measure? Also, I heard when you buy a Pandora battery, you need to install firmware upon first boot. If my PSP already has Custom Firmware 6.20 Pro-B7, will I need to install a different firmware?

Someone please help me out..

Oh and the PSP is a 1000 model

What did you end up going with?