cheapest way to get hemi 3g going?

Given the parameters that you've mentioned. Not wanting to hack the stock harness, not wanting to run a carb. The hot-wire setup is probably the cheapest and easiest way to go. You might save a few bucks finding a computer and having hot-wire program it, rather than buying one of theirs.

At just under 2K it is slightly more expensive than Megasquirt but it is basically plug and play. A bunch of people on this site have used the Hot-Wire solution with good results. Customer service seems to be good and the overall quality of the product is excellent.

AEM, FAST, and Megasquirt all have a pretty steep learning curve. Yes, AEM (sold under the Mopar Performance brand), and FAST come with a starter tune. But as others have figured out these tunes need a lot of fine tuning to work beautifully. A thread I read online (not first hand knowledge so take it with a grain of salt) from a guy who used the FAST setup claimed that he had to spend over a $1000.00 to have his car tuned after installing a FAST setup on a 6.1L Hemi.

Now that was a few years ago and now FAST uses a wide band O2 sensor and has a self-tuning feature, this should greatly reduce the need for dyno time. Although at over 3K, probably out of your price range.

Save your pennies.

Regards,

Joe Dokes