A 4.3 is certainly not the ideal V6, since it's just a 350 minus 2 cylinders. GM's best V6s are the 3.8 turbos for performance or the old 305s for grunt.
If you want to run injection, it only really requires 5 sensors. Once you get it down to that it becomes much less complicated. There's another thread about efi on a 235 that covers it all pretty thoroughly. The style of engine doesn't matter.
Devin
