I've had some poor experiences with previously modded cars, so make sure you know the platform well and what it will take if you purchase it and need to resolve issues.
2006 Subaru Legacy GT (highly modded the wrong way) - Fuck that thing. We traded it back in four months later and it popped the engine soon after.
1987 Buick Grand National (highly modded the right way, almost) - Ran great until I popped a head gasket. PITA to repair, sold it back to the previous owner (<3 Jeff), he popped it a few days later. Turned out the guy he bought it from blew the engine and rebuilt it with NA parts.
1995 Ford Mustang Cobra (mildly modded with all bolt-ons) - This thing was a nightmare when we bought it electrically. After many hours of labor, it's almost back to normal as it should have been. I have the harness for that final step and it should be 100% by fall.
2000 Pontiac Trans Am (lightly modded) - Redneck engineering. I spent all weekend unfucking the absolute worst header-back exhaust system I have ever seen. Ever. Ever seen something so lazy as to install headers, not install O2 bungs for the sensor 1 locations, and run simulators instead? Yeah. Now it's running fantastic, sounds good, and knows how to adjust for A/F.
I didn't know the Cobra platform, if I did it probably wouldn't have been nearly as bad. I know quite a bit about the 4th Gen F-Body platform, so this was easy to diagnose and repair.
That being said, I hope you're getting another WS6 or a Firehawk