Our last two karts have been shifter chassis and we’ve run TaG with both of them. The upside is the shifter chassis is it has the pivot points for the shifter leaver, comes with a shifter lever, shifter rod AND front brakes. The front brakes are not a liability for us as we road race/enduro where front brakes are allowed. Many sprint classes do not allow front brakes but you might be OK with them on a shifter. Be sure to read you track and class rules.
As for support, the kart shop owner will help you out. You probably won’t ask any question that he hasn’t answered before. He’ll answer your questions and do the same for the new karters after you. At the track, some of your competitors will help out if asked.
I don’t advocate this, but you might want to get your wife involve. You’ll need a hand to get your kart from the racing surface onto a stand. Also you’ll need someone to keep track of changes to the kart. Pen and paper is a good tool to have. Things get hectic in the pits between practice sessions and someone to take notes will help when you reflect back on a day of racing.
LAD Specialties customer / tony kart / rotax / kt100