The aftermarket for these cars is awesome and the LSX community is generally very tight knit and mature. The sponsors for this site will generally be the best way to get the rights parts for your car, they will help you get the parts YOU need for what YOU want not what THEY want to sell you.
F-body meets are fun and every state has them. Also since the LS series motors are still in production and very popular the aftermarket is getting bigger and better.
As far as the Camaro or TA.. the TA has nicer seats (lumbar support, nicer looking, more comfortable) and most likely a few other things. I agree the TA looks more menacing but if you are gonna "mod the hell out of it" as you say, take a look around maybe there is a hood for the camaro you like (SS, Sunoco, Harwood, etc.) and teach people to fear your camaro

I love the look of 315's on an 11" rim on the back of the camaro with a nice cowl hood
"An SS camaro looks like it can kick your ass, a Trans Am looks like its about to"...
Then there is always the sleeper look, play off of the ignorance of people that fear the SS but not the Z28 or fear the WS6 but not the Formula.
Keep in mind your plans for the car and use that to buy, if you plan on just minor things and want a #'d car get an SS or WS6/Firehawk... if you plan on pretty extensive mods and making it a real street bruiser or drag car then get a Z28/Trans Am/Formula for cheaper and save money for mods.
Also do you plan on a lot of drag strip racing or will it be more of a street car?
Use that to decide on A4( 4l60E automatic ) or M6 ( T56 six speed manual) ?
A4 will yield more consistent drag times and a stall/cam/gears will net you 11's I have heard. Whereas the M6 will put more power down, be more favorable for steep gearing and larger cam and be more fun to drive on the street ( my opinion ).
Good luck with you decision. I know you will make the right choice ......
(M6 Camaro)
