I would 100% recommend just grabbing a Neon dash. Take your time with a dremel, and boom - SRT-4 gauge fits no problemo.
While you're there, stock up on:
- sunvisor clips from sunroof cars (non-sunroof cars are different)
- washer nozzle hoses and connector, don't bother with the nozzles themselves, they'll just crumble
- inner door handle screw covers from 2000-2002 Neons (little round circles)
- trunk lid liner from 2000-2002 Neons
- boost solenoids off of PT Turbos
and any other interior trim showing wear, etc.