Just for your reference, I just did the X-pipe w/ resonator delete on my car this last sunday...
The thread is here:
http://www.camaro5.com/forums/showthread.php?t=82032
I went with the Dynomax Axleback, hoping it would be louder, BUT I had to go a little farther. Deleting the resonators didn't make a HUGE difference, but it is noticeable, probably more in person than on the videos. Deffinitely louder under load.
There is a before the X-pipe and resonator delete, and an after X-pipe and resonator delete video, both with the axleback installed. I don't have a video of stock. Check it out, maybe it will give you an idea if doing the x-pipe & resonator delete is enough.
I pretty much did mine myself for $111 dollars. If your axle back is like mine, it doesn't go past the front of the axle, and you still have factory pipe. Look into the Edelbrock 6717 setup (
http://www.summitracing.com/parts/EDL-6716/ ), you have to cut your factory pipes, but I think it would probably work fine with your borla axleback, and not hurt your wallet. Unfortunately, I built my setup before I ever knew this Edelbrock piece existed.:-/