Which wiring direction for TBI?

So I have a 1979 Chevy truck that I would like to tinker with and put TBI on it. I joined this site and have been reading and trying to get a feel for if I would be getting in over my head. Quick breakdown... original 400sbc in factory form with a TH400 transmission. Literally the ONLY part I have for a possible TBI conversion is a later model 454 throttle body. Getting all the mechanical stuff sorted out like fuel system and sensors is not an issue for me, the big issue for me is the wiring and tuning. Because I am not swapping in a stock TBI motor I can't just use the stock computer with a stock tune and run it, mine will require a tune.

My question is, because I can go any direction I want, which direction will be best?
-Stock harness and ECM (as outline on this site)? I can go to a PAP and find this stuff, but I still need a way to datalog and burn chips. There is a Moates APU1 AutoProm a gentleman is selling on another forum site. I would need (want!) to pick up something like this because there is no one around me that does chip burning.
-I am also intrigued by a MegaSquirt system. It looks like the above but all combined into a single integrated system.

My head hurts from all the reading I have done over the last couple of months. With the intention of possibly using this same system when/if I rebuild this engine, what direction would you recommend, and WHY?? The why part is important. Thanks in advance for any counsel you provide.