The Intrepid chassis is an excellent choice, but so are many others.
Tony Kart is awesome, and the replacement parts are available anywhere for a decent price
Top kart is also real good and very responsive, will do very well as a front runner, and yes parts are available anywhere for cheap
Kosmic Karts ( OTK ) I noticed in a short period of time they will sag in the middle of frame
Arrow karts are also pretty good, Birel karts are good also, and many other Italian karts
CRG karts are really good, but I have noticed a negative issuethe braking system is extremely expensive ( $600 bucks per rotor? )Also they seem to fatigue at the bearing cassette brackets and crack, or brake off ( a few people re weld them )
The big question is: How much track support and local shops are around your area, and How many people are running them, and of course How much money are you willing to spend?Anyhow, I hope this helps.