Always go for a 2T. Being able to see exhaust AND cylinder head temp in an air cooled motor is the way to go. Or exhaust and water temp………..
AIM actually has people at major races to help out competitors. Never saw anyone from Alfalfa. Replacement sensors are easily available from almost every kart shop/dealer or can be borrowed from others.
Racestudio software can do a lot.
When you go to sell, a 2T will have a better chance to sell.