I did mine exactly as the OP did, except I used MagnaFlow 35124 tips. Got the "Bushing" pipe material from AutoZone (see pic for P/N) Only recommendation is to use maybe a 2" T-bolt clamp. The 2.25" T-bolt clamp I got was 2.25" when fully closed, not enough to fully clamp the tips on as tight as I'd prefer. Total cost for this project was about $90
Original Tips:
New Tips:
Tips off car:
Adapter Pipe:
UPDATE: since OP deleted DIY, here is a quick rundown:
-buy weld on tips and cut 4 slots in the back end so that the tip has some flexibility during clamping.
-FRS has an odd exhaust size, (2-1/8" and tips start at 2-1/4") so an adapter is needed. I bought one at autozone that I then cut in half and sliced down the middle.
-use a t-bolt clamp to attach the new tips with adapter to the exhaust. You could trim exhaust as needed, but I just left the 2" expose poking through a little.