Best donor for MPI

My question is what would be the best donor vehicle/year for Multi Port Fuel Injection? I would like the benefits of OBD2 but Ive heard there may be some reasons to avoid the first years of OBD2? I already have a 93 ram van with 5.2 OBD1 and a late 95 ram van with 5.2 that is OBD2. I have a magnum 5.9 that I want to run in my 70 valiant. I could take the harness and fuel injection parts from my 95 van and find a 5.9 ecm but I am a little wary of mix and matching parts from different vehicles. It seems that security system may be an issue on later magnum donor vehicles so lets hear what you have had success with and what offers the most support as in programers and aftermarket upgrades.

I would use the stuff you have, it sounds like you have the obd 2 harness that would work fine with the 5.9, and you should be able to use whatever year obd2 PCM with it you want. I don't have any experience tuning those though, so I can't help you there. Depending on the year engine you may have to use sensors off the 5.2, because of the connector differences. I have a 95 Dakota that was a v6 and now has a 99 ish 5.9 in it, and I took the sensors from the six, so I wouldn't worry too much about mix/match.

Personally, I'd consider using a Megasquirt 3 with the MSX expansion board or the Megasquirt 3 pro. You can run it with all the stock parts if you want and easily change later on. It won't have quite the diagnostic capacity of the OBD II but you'll have a lot more flexibility.

Goldduster is right, if you are planning to build an upgraded engine for your car, or even plan on using certain camshafts. It really depends on what you are planning for the car, a mild 5.9 with intake, and exhaust will be fine with factory stuff, but beyond that you will want to upgrade. The factory diagnostics do help a lot with daily drivers though. Also cost can be a factor to consider since you have all of the factory pieces. When I did my magnum swap it was similar to the stuff you had laying around, and with fuel system, oil pan, and misc stuff my total swap cost was around $400. I figured if I ever built a nicer engine (not likely for a c body sedan) I could upgrade as I went. I haven't priced megasquirt stuff, I think it's pretty reasonable, so it it a good option as well. It will be a cost on top of the other swap pieces though, so just think about what you want to do with the car an go from there.

Thanks for the response,
my thoughts were to use the obd2 stuff I have and make a reliable fun driver. Then, upgrade for more power. I am familiar with the stock stuff but not sure about modifications especially when you get past headers and intake mods. I have read some on the Dakota R/T forums about modification to fuel injected magnums. I just wanted to gather the correct parts the first time around and not find out that I should have gotten a different harness that works better than what I have already.