Megasquirt is a build it yourself drop in replacement for the ecu. It looks very interesting but I have no experience with one. The advantage (as with all things open source) is that you know exactly what is going on and are not locked into any one supplier.
http://www.bgsoflex.com/megasquirt.html
http://www.msefi.com/
www.efilive.com click on downloads, then efilive v4. V4 and carbytes live on this page.
Mike