[aknovaman]

Cheapest is reworking a factory harness by yourself from u-wrench-it and all used parts along with a mail order tune or a buddy who has credits that tunes for cheap. I have built factory, Microsquirt, EFI source Megasquirt MS3 plug and play LS1 with boosted and traction control as well as the holley systems and others. They all have their merit. to me it all depends on how big your wallet is and if you can or are willing to do/learn it yourself.

Does the Terminator have traction control capability built in or do you have to buy more parts/piece/interface modules?
Megasquirt has it built in already. Last I checked, there are plenty of Megasuirt extremely fast cars running at Bonneville and Drag week competition that are beating the big boys.

To each their own.