fuel injection

I'll be sure to post a lot of details on it when it's up and running. I work at a place that's got a chassis dyno so we'll be sure to get it really tuned in.

Sequential times the injectors to the cylinders, batch fire fires them either all at once or in two separate banks. For example, my Dart is wired so the first three cylinders and the back three cylinders alternate firing. Sequential can get a smoother idle and better emissions, and has the possibility of tuning the fuel differently for different cylinders, although tuning a motor cylinder by cylinder is a royal pain. Batch fire is cheaper and simpler to configure - you can just get the thing running off a Lean Burn distributor to control fuel and spark, or even run fuel only and feed it a tach signal off the coil.

I work for a Megasquirt seller - http://www.diyautotune.com - and we have an online price catalog there. For the computer and wiring components, prices can be anywhere from around $400 total if going with solder it yourself kits to upwards of $1000 if ordering a ready made unit with a bunch of extras. The sequential version is expected to be around $600 or so for the ECU when it comes out, add another $100 or so for sensors. The main Megasquirt manual is here: http://www.megatune.com - though it's moving to another server and if it is having trouble you can view a mirror copy at the DIYAutoTune site.

As for what else is out there, I'll divide them into a couple of categories. I may forget a couple of them.

Basic batch fire systems:
SDS - http://www.sdsefi.com
Holley Commander - http://www.holley.com
Retrotek - http://www.retrotekspeed.com/

Some of the more common medium priced sequential systems:
Accel - http://www.accel-dfi.com
FAST - http://www.fuelairspark.com
BigStuff3 - http://www.bigstuff3.com
Edelbrock - http://www.edelbrock.com

Some of these can get pretty expensive, but have lots of features:
Haltech - http://www.haltech.com.au
Motec - http://www.motec.com.au
AEM - http://www.aempower.com

A slant six isn't usually a very complicated engine to deal with, so chances are the ECUs in the third category will mean paying for a lot of features you don't need. Megasquirt is going to be cheaper than most other options, although it was designed as an educational project originally so there's going to be a bit more of a learning curve involved than some of the ones from the medium-priced region. (Though it does get steep again at the high end of the price spectrum, just because of all the features you end up dealing with.)