i was in your same situtation a while ago and i went blower. HCI requiers less supporting mods but doesnt have the same power possibilities the blower has. i priced it out and HCI when all said and done would have cost me 3k. i was able to find a vortech with all the supporting mods for like 400 dollars for than the HCI cost.
i went with vortech because the s-trim is the cheapest one out there and is capable of 600hp.
you arent going to need the injectors,MAF,fuel pump with the s-trim tuner kit. the FMU and BTM is fine if u run conservative boost and get a good tune. some say u dont need a tune with that set up but i would. people dont like the FMU cuz its like a band aid for not having a big enough fuel system but its designed to work fine with the stock setup. although, once you want more power, u will need to go and upgrade that fuel system. if you have the money now, upgrade the fuel system but if not, its no big deal, just stay conservative. FWIW i was going to stay with the FMU but i realized it was more cost effective to upgrade now so i wouldnt have to get another tune in the future.