Psp Upgrading Downgrading Non Flash HELP !!!

Hey there, right first of i currently have a 2.60 psp with the better motherboard (the non T8 one) and is currently running the Eloader 99 (the one where you got to images and select it for it to load) to play genesis, Snes, Master system, GB and GBC etc. My Problems are these i would like to play some later firmware games but dont want to upgrade so that i lose my homebrew ability and also i dont want to downgrade incase i screw up my psp, i have heard of a Reverse devhook which doesnt write to the flash and that can emulate later firmwares to allow you to play later games, so i was wondering if some one could explain this to me and tell me how would i go about doing this, any help would be appricated

also i dont have gta lcs so i cant use any method that uses that and i could upgrade to 2.71 if need be

Thanks :D

Roxas_13

P.S i am a bit of a newbie when it come to psp emulation so try to explain it in Petarded terms lol