Redmist's build is very nice. Mine is somewhat similar but I used a FAST XFI controller. At the time I started my build the Megasquirt was batch fire only and no spark control. That and the fact that I wanted someone to speak to if/when I needed support. The new Megasquirt is a far cry from the original and of all the systems is probably the best bang for the buck but regardless of which way you go, it will be at least $2k by the time you are done. Most systems use the standard GM sensors etc. so they are cheap but don't skimp on the fuel system. I looked at a surge tank system but in the end, I built a custom fuel tank with an Aeromotive A1000 pump. The surge tank idea is great but I didn't like the idea of another tank as the only place I could really mount one was behind the grill up front.

You say you already have the spark control so another way to cut out some costs is to look at a batch fire system. That eliminates the need for a cam sensor although the Jeep sensor Redmist and I used is cheap.

Ask lots of questions and do a lot of reading to familiarize yourself with the different systems and what each offers and above all, have fun with it.