You's have it all answered there!
Just to clarify,
@forester dave, Your car is the FS5 chassis, so all scruffs advise relates to you! none of coopster's! I whole heartedly agree with scruff, I put sti springs on mine and she was on the bump stops, so maybe go for WRX springs, and the rear anti roll bar is so easy to fit and will make a huge differance!
@ PatK, your car is SG5 chassis and is not at all like any impreza, but as coopster says, there are plenty of foz specific upgrades you can get! if you car is Irish/uk car, then as coopster says you'll need to change your rear struts because your should be self leveling items, but if she is a jap import, you'll be grand,
Either way, rear antiroll bar and 4 wheel alignment is a must!!! I run 1.5deg neg camber on the front and 1 deg neg on the rear, with no toe in or out!!
And as scruff said, Any scooby brakes will bolt straight on! as long as your wheel clear them!
Best fo luck
Dan