Stupid Distributor Questions

I am looking to replace the stock single point distributor in my 69 340 Dart for an electronic unit. My car is currently all stock, and has a 727 automatic trans with the stock 323 gears, stock AVS carb and factory cam.
I have read of the Mopar Performance electronic conversion kits available, and I'm leaning that way because I THINK it will have the right (or at least close) advance curve built into the distributor out of the box, and also because it should have everything I'll need for the project in the kit.

Will the advance curve in the MP distributor work well for my application?
Is the mechanical advance in the MP distributor adjustable?
Will I need to use a different spark plug after I install the MP kit?
What spark plug wires will I need?

I have also seen electronic conversion kits that are NOT from Mopar Performance. Are these kits primarily used for the elimination of points and to gain the benefits of an electronic ignition without being a performance application?
Is there a difference between a MP conversion kit as opposed to a replacement conversion kit?

Also, if I buy a MP conversion kit, will I need to replace any other parts of the car in order for it to work? I think I remember one of you more experienced members mentioning that the stock mechanical voltage regulator will also need to be replaced, but I don't know why. Would the alternator need to be replaced as well?

My car runs lousy. It pops through the carb occasionally, and I can feel it surge under light load. The distributor that is currently in the car is a generic auto parts replacement for a "non hi performance" application, according to the counterman. I run the vacuum advance off the only available stock port on the carb, and if I disconnect it, the idle speed drops so low it will almost stall, so I assume the factory connected the vacuum advance to manifold vacuum.
Based on what I have experienced with this car so far, I would say the idle timing with the vacuum advance connected is way too far advanced, but with it disconnected, my base timing is at 8º to maybe 10º BTDC. Connecting the vacuum advance again returns the car to the correct idle speed, but the car will ping at higher RPM with my foot to the floor. If I advance the base timing and leave the vacuum advance disconnected permanently, this will create an even higher total timing, and make it ping even more.
I don't want to fool around with this incorrect distributor when it would make much more sense to use an electronic distributor that is for a performance car, and will hopefully have the correct advance curve built into it.
I wish I had the original 340/automatic distributor for the car, but it was gone when I bought the car. I have seen some on eBay advertised as original 340 distributos, but I have no way to verify if they are really 340 distributors or not before I buy them, and I don't want to get burned again. Besides, the prices these sellers are asking for these old parts is enough to make me buy the electronic kit from Dodge.

As always, I am open for any and all suggestions. What would you do if it was your car?

Thanks in advance for taking the time to explain it all to me.

George