iOS iphone official SDK and non official

Hi everyone. just a quicky.

i have recently installed the official Iphone SDK into my leopard system and its all working lovely. however, i would like to use the non official one to allow me to write software for the "hacked" iphones.

can i run the pair together or do i need to uninstall xcode etc and then install it again then the unofficial SDK?

any help would be greatfully recieved as normal.

thanks
kris