I've handled the parts to Kibler's kits.
You will NOT find a simpler kit to assemble short of buying one of the "sand and stain" kits from the major production gun players. TC used to do this a lot, Lyman might still...where all shaping/material removal was done...you just smoothed the wood and stained it.
Kibler is sort of "in between". You don't have much shaping or metal removal to do. You do have some drilling/tapping to do, IIRC. Inletting is essentially done. I don't think much, if any, has to be done. Metal is in the white, and I sort of think tennons/sights have to be installed, but I'm not positive.
I've talked to Jim Kibler in person at shows. SUPER nice guy. If anyone is curious about the kits, I wouldn't hesitate to contact him directly through his site contact information and ask questions.
I also know within the next year, he plans to release a second type of rifle in the same kit configuration and is planning more styles to be released as kits in the future. He's said the next one up will be a Revolutionary War/Pre-Rev War style gun in larger calibers than the current kit offers.
If you go to Dixon's, they have everything you need to build a gun....precarved stocks, barrels, breech plugs, locks, castings, etc. Even have the long deep-boring bits to drill ramrod holes if you're so inclined.
There's also classes through Jacobsburg Historical Society near Easton where you go every Sunday for 9 weeks (starting in like 2 weeks I think) and build and Lancaster rifle in 50cal with a 42" straight barrel. The cost is about the same as a kit, so you can sort of view it as getting the instruction for free.
Lots of options.