MSD, HEI, or OEM?

Been wanting to upgrade the ignition on the duster. Right now it has a Mopar chrome box with a 2 ballast setup. Wanting a 12v to the coil setup, probably a larger plug gap. I have a 12v coil already and an MSD box. I've used the MSD 6A before a few years back but now the box seems fried. Doesn't fire over and no 12v to the coil.

Motor specs are la360, touched up x heads, ld340 intake, 11:1, headers and duals, MP .528 241/241 solid flat w/ MP roller rockers I think they're aluminum. 600 cfm edelbrock @ 6500' elevation. Timing is set at 19 initial, 34 total, dist recurved for mech weights only. No vacuum advance.

I've ran HEI in a truck and liked it, it was rather cheap. I think $25 for the control unit and an extra fits nice in a glove box.

Mainly hoping for a better idle by adding spark energy at idle. Runs choppy, 10-11 inches vacuum at 1000 rpm and 5-6 inches at a steady 800 rom curb idle.

What are you guys running?