Who supplies the most bang for the buck in a electronic ignition distributor kit for a stock build street driven 440 ??

My pref is a stock 70's electronic dist with an HEI module mounted underneath ( www.designed2drive.com has a nice mounting bracket but it is pricey & you can easily make it yourself). An E coil/no ballast then dial in the dist subsystems in order/check rotor phasing/reduce lower axial play to .005/reduce lower tang/intergear clearance to near zero/reduce rotor tip to cap terminal clearance to .015". Many choices out there to choose from.

Junk yard or maybe Rock auto

Ebay

$25 is pricey? thats dirt cheap when talking mopars.. and you would easily have more then $25 of your time into making one as nice.

I prefer the old Mopar electronic ignition conversion kit with the orange box. On the newer ones you can adjust the maximum mechanical advance inside the distributor (no timing limiter plate needed) and you can adjust the vacuum advance with an allen wrench. Cheap, simple, complete.

For $110 and the cost of a used distributor, you can have something that you can tune to your combo.

Pick up a used 440 mechanical advance electronic dist, just make sure the bushings aren't worn out.

Install a J685S limiter and 6 spring kit from 4secondsflat, $40.
http://www.4secondsflat.com/Mopar%20Mechanical%20timing%20limiter%20plate.htm

Control it with this ECU, available from Jegs, $35.
http://www.jegs.com/i/JEGS-Performance-Products/555/40805/10002/-1

Use the recommended coil, available from Jegs, $26.
http://www.jegs.com/i/JEGS-Performance-Products/555/40105/10002/-1

Use the recommended ballast, from Jegs, $9.
http://www.jegs.com/i/JEGS-Performance-Products/555/40103/10002/-1

Summit used to have their own version of the MP kit, don't know if they still stock it. The newer MPs are filled with mallory guts - use with a 1/2" shaft collar and mallory upgrade kit 29014.

SUM-850005 for the kit or SUM-850005-1 for just the dist.

#1 your post offered no relevant info toward the OP's question (which is what we are here for). #2 You (also) missed an important component to this: The satisfaction of making it yourself.

It seems MP is making ECUs yet?

http://www.jegs.com/i/Mopar-Performance/312/P4120534K/10002/-1

Assuming, based on your question, that the car is currently wired for points ignition. Similarly assuming that the Bang you are seeking is low maintanence and reliability.

For those goals on a stock, street driven engine you want a system that provides the stock timing curves and coil that will be best from idle to 3000 rpm.
Options*
* Use stock single point distributor with Pertronix Ignitor inside. One wire will need to be added to the harness.
* Install a used or "rebuilt" distributor for a similar vehicle and engine from '73 up
+ plus the wiring harness for a mopar type ECU and the ECU from a parts store or junk yard. (similar to B5 Bee suggested)
or
+ plus the external HEI module etc as RapidRobert suggested.

The Mopar Performance chrome and orange ECU reliability has varied over the years. So that's a higher risk option. The Mopar Performance distributor with Mallory internals is reliable but inherently has a curve shape that starts to come in quicker with higher rpm, instead of slower. You can spend hours trying to get it to a reasonable compromise. A chrysler built distributor is a better starting place even if its not quite the original curve.

FBO limiting plate. Shouldn't need it since the engine hasn't been hot rodded.

I agree, petronix is probably the best choice here.
It was literally the fastest change I have ever done when dealing with a distributor. Because you don't have to pull it and get everything lined up again. lol. 15 min and it fired up again.
you can even find used ones pretty cheap.