Just buy a plain white psp skin and print what you want on the skin there is a program you can get to put in adobe photoshop to make a skin in adobe that will be a perfect fit for the psp. Heres the link to a tutorial on how to do the psp skin
YouTube - How to Make your own sony psp skin!! and heres the link to buy a white psp skin
PSP Skin - Solid State White @ DecalGirl.com .