The winning chassis were the ones setup by the most knowledgeable tuners....they'd be winning on any brand. Pick something with good factory support and local parts availability and then go test and tune from a known good baseline. There are no shortcuts other than buying known good stuff to start, then adding in all the time and money you can spare. The top brands are all within .001s of each other on a theoretical basis, I'd wager. The purpose of a chassis company is successful marketing leading to sales. The purpose of a racer is to win. Those are sometimes consistent, sometimes not.
Ted said it best... pick a manufacturer you can trust to build a good kart, good parts, and most of all, provide support - whether by phone, email, or in person.
Obviously, I'd recommend PRC (I may lose my job if I didn't

), but having part availability and someone you can talk to is most important (outside of the performance of the chassis itself - which most top manufacturers win every weekend throughout the country).
Plus, it helps that one of those guys that works for one of those chassis company's supports and uses Bob's 4 Cycle from time to time...
