PSP at 1.50, Which Custom Firmware should I get?

Ok, basically I got 2 1.50 PSPs, one for me and one for a friend. I want to load them up, so yeah which custom firmware is good.

All I really request from the firmware is for it to be able to flash back to 1.50 if I wish too.

Also, could you post a quick guide on how to upgrade a 1.50 to the custom firmware you are posting.

And one last thing, can you link me to good emulators for the following consoles.

GBA
N64
SNES

Thanks in advanced guys. :thumbup:

Edit:

Ok, after doing some research, I am using 3.71 m33-4 on both, all I need now is some list of some quality emulators. Thanks in advance guys! :thumbup: