Uhh, I thought I had stumbled upon a sarcastic post...until the 6th lengthy and heart-felt reply.
These are Subarus we are talking about here, and this is the Normally Aspirated Powertrain page...not the "rice it up" page. The classy thing is to get a real high-flow muffler, high-flow cat, and some good headers. Then go make friends with the guy doing the work at an independent exhaust shop. Then have him fab and install you a perky, tucked-up-in-there, system of like 2.5" or 2.75".
Oh also, big tips let out some less than great sounds, and can drone on the highway...instead have a look at some of the best sounding super cars:
Note that the trend is dual, medium size, exhaust exits. Or even dual exhaust.
I encourage anyone with a Subaru to kick it old school, and operate off the, "GO BEFORE SHOW" mantra. Lets save some rice for starving kids in the 3rd world.
(let the flaming begin)