ok so ive been reading this forum now stop now for a few weeks. going through mod list and everything. but on thing ive yet to see is a extended drive shaft on the lifted guys trucks. is it not necessary? has anyone made a list of everything you need to lift 3, 4, 5, 6 inches? if not can someone. i think it would be pretty helpful and cut down on threads having it (if its there i missed it when i search). it doesnt make sense that you can lift 6 inches and not extend anything like the driveshaft. thank

From my knowledge - others probably have more than me - this is a pretty basic pattern.
3" - no change for most. Some need a 1" T-case drop (I did).
4" - same as above
5" - 1-2" t-case drop or a SYE. Sometimes the drop will work, sometimes not.
6" - SYE recommended.

thats a good start but what are the other things people should consider? longer control arms, etc....

sorry, was just answering the drive shaft question.
For a 3", all you need is the leafs, coils, ubolts, and hardware for most. Some people need the t-case drop like I did and it's a good idea to do quick-discos for the front sway bar. 1, it keeps the stock extensions from bending when it's connected and 2, it lets you disconnect for going offroad and get more flex. I also did longer brake lines (95 YJ on the front, 96 Dakota on the rear) so there wasn't any strain on them when I flex.

4" is the same, but LCA drops/ adjustable LCA's are helpful. Same with an adjustable track bar. Steering stabilizer is a good move as well. Others may add more to this one.

Not sure of the full list for 5 & 6"

There is no specific, every vehicle needs xx. There are recommendations. I would say for the most part 4"+ should probably get an sye, longer arms or drop brackets, and track bar.