Jason!
Be sure to take your time and get the right car, don't let the excitement of getting your first Scoob cloud your judgement, I know it can be hard
If you are planning to mod the WRX, bare in mind what you want to achieve and weather saving up that bit extra for an Sti is worth it. You often find you get a lot more for your money if you can grab a good one from the start, especially when you bare in mind the uprated turbo and drive-line set up of the Sti.
Best of luck!