after market help

ok i want to buy another lude to turn into a street racer. wich yould be better, 4th or 5th gen?? wich has a larger aftermarket?
i want to leave my current lude a stock* as possible so i havent really looked into it. and plus i just got it. where can i find a front lip spoiler for my 4th gen?? thats all i want* but i cannot find it.
and would it really be worth it to drop a turbo in or not? 4th or 5th??thank you