As long as you're paying for PS, check out Codeweavers' Crossover Linux. You can run native Windows programs under Linux (Crossover is a tweaked version of Wine).
It looks like Photoshop isn't quite there yet though: http://www.codeweavers.com/compatibility/browse/cat/?cat_id=...
It is one of the top applications that they are working on: http://www.codeweavers.com/compatibility/toplists/