If you've not done this sort of thing before, then the Strat kits are a good start. Simple wiring, the bulk of it already done for you. The body and set up are relatively simple and don't require a lot of specialist tools or skill (With the exception of fret levelling and nut prep).

Standard Tele would be a simpler build that a thinline, but it all hinges on ambition and your skill set. Best of luck with it!