[cmiovino]

The tS isn't as complicated/limited as you might think from a mechanical and performance standpoint. The tS has different wheels and tires, stiffer springs, strut bar, and aero vs the performance pack model (plus the interior/color changes). There are also some extra draw stiffeners on the tS and higher model STi's I believe, but don't quote me on that. The performance pack adds the Sachs dampers, Brembos, and different wheels vs the base models.

Point is, any BRZ/FRZ/GT86 springs will work on all models. Any struts/dampers will work on any model - with the Sachs dampers being the same between the tS and performance pack.

The wheels are 18" vs the performance pack 17's, but both are 7.5". 225 or 235 work well. Just be aware some tires run wider than others. 225 will fit across all tires, but some performance fires run wider like the Falken Rt660's and Yokohama A052's. 235 might very close with these. I believe offset on the both wheels are +48. I personally run a 3mm spacer to give some extra clearance on the cheap. 225/40/18 would work just fine with the stock struts, however if you go to a coilover in which the body is smaller than stock (all usually are), then you can easily fit 235 or even 245's. Then problem with 245's then is number feel and tire bulging with a 7.5" wheel. I'd stick with 225's and maybe 235 with coilovers.