new to aston martin buying db9 c.p.

hello this is mike,in sept''or earlier if i find the right one'' i plan to purchase a 05 06 db9,i have some questions and concerns,1,should i stay away from a 05 being it is the first prod year? 2what kind and how long are the fact. warranty's/what are some common probs.with these cars?''every car has them''also i plan to add a body kit i prefer a sub tile change when doing this and like to stay o.e.m.,my first choice would be purchasing dbs parts but after researching on this forum some members say a.m. is reluctant on selling these parts for retrofitting etc.my second choice is the kahn anyone have experience with this kit? the mansory is a little over the top for my taste altho i like the rear bumper and defuser.any comments and photos would be appreciated thanks mike,