heads for 340

I'm in the beginning stages of trying to round up parts for a 68 Dart street car. Probably wont see any strip, just stop light racing and sumthing to make the chevys take notice.
I've got a '70 340 block w/ stock crank and rods and a LD340 intake I am planning on using. My main question is what would be a good pick for heads? Ive been reading up on previous posts, and have found some great info. However i cant seem to decide which way to go.
I've got a set of 915 J's, 587's, and a set of X's, all need everything done to them. I've also got a line on a set of 308's that would need gone through. I am leaning towards 2.02's w/ a little bowl work in whichever head might be the better choice. My main concern is spending money right the first time as it is going to be a budget build, but would also like the best performance i could get for the money spent as well. Would i be ahead to put 2.02's in the 587's if they already have hardened seats and use them? Or spend a couple hundred and get the 308's and have 2.02's put in them? Would i see much gain with the 308's?
thanks for any input.