Hi One and All

I am new to biking and just bought a ZX6R A1P (Believe that is the full name), and DAMN I love it, goes like stink! Cool. I want to change the standard screen and put in a smoked double bubble but whenever I check with people I aim to buy from on ebay they say that whatever make they are selling will not match. Does anyone out there know if it truly is a problem and i have to get the model specific or will a J2 or J1 screen fit as there are loads of them around and a lot cheaper than the few A1P ones I can find.
Any suggestions or advise would be well received

Cheers All