Manky, I'm looking at the EFI kits, too. My application is SBF, and the guys at the House of Boost
http://www.houseofboost.com/ have schooled me a bit on some details. Below 600hp a batch fire system, such as found on many OEM systems, works fine. The 600hp break point is due to the size of the injectors needed to run full power, and the fact that they don't have enough turndown to provide a controllable idle and part throttle rpm - you are pushed to direct port injection, controlling each injector individually, even going to multiple injectors per cylinder for the big boys. Several companies are offering EFI kits which have everything needed in a coordinated package - Edelbrock, Hilborn, FAST, Holley and others all have offerings. Edelbrock & Hilborn both have systems using a FAST XFI ECU which is a windows based laptop tuning interface. One FAST system is made to replace an existing carb, and has a self tuning system made for the novice, and giving the appearance of a carb under an air cleaner. Others, like Inglese and Hilborn, give a race engine appearance with sexy velocity stacks. Inglese has a really nice look, but a really nice $$$$ price tag, too, a bit over $6k...and for cruising you have the need for filters hiding the sexy appearance.
There are some guys on here who have cracked the cases on OEM ECU's, and adapted them to their applications. I'm not that well schooled on that aspect, and am more aligned with plug & play. The ECU from Big Stuff 3 (BS3) seems to be the new system of choice from the shops building systems from scratch. BS3 is headed by the guy who directed much of the development of the FAST system, and the company is small - him and his two sons as the major players as I understand.
I will be either going with something like the Edelbrock kit, if they ever release the SBF version :confused:, or as a fallback may let the HOB guys build me a BS3 system, coordinating the components for a package approach. I like the FAST self learning system, too, but on a new car/engine application I'm not tied to converting from carb, and I'm not really looking for a "traditional" induction system look.
What are you finding in your part of our shrinking world??