They are not a standard size, so you will struggle to replace them without leaving gaps unless you get some custom pickup surrounds made up, you might have to do some additional routing also.
Why in such a hurry before you've even heard what the stock ones sound like? The stock pickups are louder, more lows and less highs than typical PJs, but they sound great. If you want to drop replacements straight in, you would be better off looking at one of the newer BB models (e.g. BB235, 435, 735A) that use traditional size pickups. The stock ones on the new models are voiced more like vintage pickups (more mids/highs, less lows) and you may be surprised to find they sound as good as whatever you were planning on putting in there!