just rebuilt my 360 and I want to do all aftermarket igniton but not sure what to go with.

What did you have in mind? And how much did you plan to spend? Crank position sensor deals with all the engine timing issues. Sensor in the dist is simply for injector timing. Has nothing to do with ignition.

if I keep It under a grand ill be happy. mostly msd stuff is what I was looking at

Could do a blaster coil, and MSD smart box.... won't give you any noticeable power improvement, but, might idle smoother, and a bit better throttle response up to about 3000 RPM. Really, unless you are building a fairly powerful performance motor, the stock ignition system is pretty good. Spend the money on other stuff..... SCT tuner, Harland Sharp 1.7 roller rockers, headers. That would be right around a grand, and would give you a NOTICEABLE improvement.

yeah I was already looking at the headers. just thought It would be a shame to put the stock igniton system back in if I was doing all this other stuff

As said, the stock ignition system really isn't that bad. Not like these are carbed small block chevys. You would get a LOT more bang for your buck going the other route.

Oh, and: Welcome to DF!

which headers should I go with?

Shorties will bolt right in. Lots o' folks make em. They will give you some improvement, but, on your truck, biggest restriction is right where the two pipes go into the cat. If you don't have emissions testing where you are, you could get an 'off road' y-pipe. Flows MUCH better than stock..... If you DO have emission testing, you could still get the off road y, and just splice in a high flow cat, or, just pick up the magnaflow high flow cat. It's a direct bolt on as well. (instead of the off road piece)

Long tubes would be a bit more beneficial, but, would cost more, as you would have to do some other work to finish out your exhaust. Duals would be an option.... Pacesetter is about the only manufacturer that still makes long tubes for our trucks though..... they also make a y-pipe to make hooking up the rest of the exhaust a bit easier. (would make putting a single out exhaust dead easy.)

What if anything did you do about the plenum plate? And +1 on the ignition. Not much to be had there for the money.