If you have the Galant for a winter car, why on earth would you want the C4S? Porsche AWD, while good, takes all the fun out of the cars (in NA form). Understeers like a pig in the dry. Brakes are the same in post facelift ('02 and up) 996’s except for in the GT3 and GT2 models, so a turbo upgrade isnt an upgrade at all. Suspension is nearly the same, the only upgrades worth your time are PSS9’s or Motons or JIC or JRZ. The turbo stuff is marginally different, and the only real different OEM stuff you can get is the M030/ROW parts which is really just a drop and like a 25# increase in spring rate. As for FI if you want to waste your money, start with a C4 or a C2 and start going FI (turbo if you really wanna waste cash) or the ONLY good Supercharging kit out there is the EvoMS kit which runs about $8k (plus install). Basically, get a C2 or a C2S you’re in the city so you can still drive it year round. You’ll have a 2WD sports car, that’s fun, has killer looks, will be cheaper to buy, and maintain than the C4S, will be faster (straight line and corners), and more fun to drive.
Dont get the MRS, ugly, and a waste of time.
The LS1 swapped RX7 is a great idea since you already have a daily. (till you get the swap done).
Legacy GT, nice car, but what’s the point? You already have an AWD daily, seems like just a “filler” car to me.