upgrade time need opinions

hey guys, been awhile since i posted here but everytime i have you've all been very helpful so here goes. I just installed the Wizaird CAI on my GT and love it. the sound is amazing which makes me want to get my exhaust done ASAP so i'm thinking on getting the ZZP ported front manifold with power log(yes? no?) then getting a downpipe w/ hiflow cat then running that to a slp cat-back. my question is do i get a 3in downpipe or 2.5? i think the cat back would be 3 unless they make 2.5 and also, should i wait till all this is done to reprogram the pcm? or should i do it b4 the exhaust.. i also plan on getting ZZPs high velocity TB for the L36 should i take that into account when building the exhaust? thanks for ur help guys!

Recommended to get the re-programmed PCM first. I've heard of GT owners going to 3" but IMO that is excessive. The engine needs some backpressure. The 2.5" is ideal. Unless you go to internal mods on your L36, intake and exhaust mods are your quickest and probably most inexpensive options.