i think the Roush version would definitely have a higher resale value and be easier to sell later. you may want to check roush's website for more info on what else you get. that or ask the dealer.
as far as the lift/tires causing loss of power. i dont think the lift has anything do with it but the tires do. as you increase the overall diameter of the wheel the vehicle gets much more sluggish. most trucks with huge lifts/tires get the gearing re-done to alleviate this. but, you have to leave it like that or have the gearing re-done again back to stock. im sure that Roush truck already comes with what it needs, in that respect. if you buy a 4x4 (or 4x2) and put much bigger tires on it than you'll want to do this. you dont have to, but it will kinda suck. my truck had just 33" tires and it was sluggish. lifted trucks are
expensive and you wont get very much out of what you put into it (like all car modding). that's why id say just go for the Roush if you really like it and would leave it how it comes. you wont have to dump more money into it and youll get much more back when you go to get rid of it.
if you get bored of cars real easily, like i do, then i say go for the lease. it costs a little more but youre not stuck trying to sell a vehicle later. although as i mentioned above, i dont think anything Roush, Saleen, etc.. takes long to sell.
