The first thing I thought when I read your post, GES, was that you might be better off with one of the cheaper ARR cars, like the XTM X-Terminator Pro or the Sportwerks Mayhem ARR (either with or without the engine on the SW)
they come as a rolling chassis assembled, with all but radio gear to complete. the X-T and Mayhem ARR's are both around $300 new, you can tear it down and rebuild it (might as well toss in a few upgrade parts too while yer at it).
there's a guy at a track a couple hours north of me, I hear he's running a stock X-T pro roller and tearing stuff up, and the Mayhem has been rippin around pretty well too.
I don't race 1/8, but my X-Terminator has proven to take my harsh thrashings in stride. I've broken four parts in the last year
And as to Hitec servos being crap...All my cars (save for my NTC3's JR Z590) are running Hitec steering servos, and I've yet to have one fail (aside from my Stampede taking a nosedive off the roof of my house-don't ask)
the Z590 that came with your XS3 Pro will be great for your buggy, the one in my Nitro TC3 is super overkill (which is my kinda kill)
IMHO you can't go wrong with any of the buggies currently on the market. the worst RACE buggy is probably the X-Terminator, but it's tough, and if you can't finish a race, you can't win.
Just learn how to get around the track without hitting stuff, and if you do hit the track, you'll be able to dominate one day.