Look at any suspension parts for the RS. They all fit from 93-01. Even the motor stuff, like headers, crank pulleys, intakes, etc. Think "Legos", cuz that's what the Subarus are. Freakin Legos man.....fun stuff indeed. Having the EJ22 is a huge advantage already. You're only about 30hp down from an RS, but you're also about 300lbs lighter (depending on trim level, brakes, etc.....) Your car is light....very light. Keep it that way and the power deficit narrows. I think suspension components for the RS actually work better on the L/Brighton due to the lighter weight.
For a point of reference, my 96 was an AWD EJ18. I started with suspension and worked up to motor stuff, swaps, hybrid builds, etc. I have done quite well with it despite the lower power. It now sports a phase II EJ22 with a custom header, running off a 98RS ECU with a good suspension setup and is turning autocross times quicker than most RS's and WRX's anywhere I go. Sure it ain't fast in a straight line....but let that road turn into twisties? .......forget about it.....I'll see you at the next stop.