It's a 2010 2.5L NA Legacy?
Stock size is 205/60/16 (25.7")
You want something like 225/50/17. Would work fine on those rims. I wouldn't recommend the SPT's, they're crap summer tires. If you're looking for really cheap decent summer tires, you can get the general exclaim UHP ($97 on TR) or the sumitomo HTR Z III ($115 on TR)
17x7" rim is fine for 225/50/17. That's what goes on the 3.6R stock.