Wide tires is the current trend, but keep in mind that the first WRX RA's and WRX STI RA's had 205/55 tires and power up to 280ps with turbo. A stickier tire on stock wheels or on lighter similar size wheels is all you need, unless you go more than 300ps.
Check here:
http://www.type-ra.com/impreza-type-ra-specs/