4GB memory stick PRO duo?

SO im plannin on buying one for ISO storage, will it work with ISOS, and when i get it, do i just insert it into psp and format, and it will be in CFW file format, or do i have to copy folders from my other memory stick manually, and delete and add stuff i want, i know that the prx plugins will be gone once i insert new memory stick and all the crap from it will be too, but if i format will it add the folders such as GAME and GAME150 and GAME 380 and seplugins and such, thx in advance!

Yes, when it is formatted it gets all the folders set up.