Fortunatly, aftermarket EFI seems to be exploding right now. 5-8 years ago, choices were very limited, and very expensive. The software was difficult to work with, and people really struggled to get it running right.
Flash foreward to 2010. EFI is (relativly) inexpensive, easy to install, and reliable. For example, the Dynatech kit. Cheap for an 8 stack system, killer looks, and self tuning. Also take a look at the Boss EFI system. Bolts on like a carb, self tuning, and for a lot less than $9K.
http://verycoolparts.com/bossefi.htm