A set of stock 2006/2007 WRX wheels would be a pretty good budget-friendly choice. They're relatively inexpensive for a decent used set (and if they're slightly scuffed, you could lightly sand and paint them like I did with mine), 17x7 with a +55 offset, and weigh 23.5 lbs each. I had 225/45/17 Michelin Pilot Sport A/S Plus tires on them at one point (see pic), but now I use them as winter wheels with 205/50/17 Dunlop Winter Sport 3D tires. Both options fit on any 2002-2007 WRX Sedan without any fender modification.
A better choice, which will cost you significantly more money (even for a used set), is a set of 2004 STi wheels (17x7.5, +53 offset, 16.5 lbs each, and the only STi wheel with the 5x100 lug pattern that is compatible with the WRX).
If you want a relatively inexpensive set of brand new wheels, check out all the different styles and sizes of Rota wheels at WheelDude.com. You could throw a set of summer tires on those and use your current wheels as winter wheels with winter tires... there are just so many possibilities.
Good luck with your decision and keep us posted!