I was in the same place you were with wanting to have like 700hp for my DD but then i was doing research and seeing what all it involved and started off with some EFI live tuning, exhaust, intake, lift pump, and edge cts to control it all and i am more than happy with with power and have no desire to do anything besides build the tranny soon. Im at around 500-520 rwhp and with all that installed at less than 3k. So i would do upgrades like and se how you like it for a DD and then go from there if your not happy because it starts to get real expensive when you want more power than that.