#1 the magnaflow system does not replace the exhaust all the way to the rear cats, it only replaces it to the y pipe.
#2 removing cats reduces backpreasure and torgue in most small displacemeant na cars, removing the 2 rear ones might net you enough hp to make the torque loss negligable.
#3 the exhaust systems that are from borla and magnaflow currently, both are great manufacturers and very reputable, niether system requires any cutting and both are bolt on
#4 a muffler replacemeant may net you some gains in power, but nothing noticeable
#5 only the srt has the resonator stock, but the borla system comes with a resonator regardless of weather or not your car came with one
#6 changing the exhaust on these cars even with the cat back system does not give a huge increase on its own
#7 i personally run the magnaflow system, its fulkly polished stainless steel, with no resonators, sounds great but not too loud, it is a bit of a b**** to install but well worth it! there is a thread on here about installing the system, check it out! there are also alot of different exhaust clips for our cars you tube, try looking around on there to find the sound your looking for. most of those people are also members here! hope you find what you need!