small block heads for a long distance cruiser

I'm gathering parts to build a smallblock for a Dart that will be a long distance cruiser. It will be a 340 or 360 and I know that there are lots of new head possibilities out there. I want to use LA valve covers and intake. What are folks using that they are pleased with. A nice mix of decent gas mileage and responsive street and road performance. This will not be a drag car, except to see what it will do a few times. It will be mated to a 4 speed overdrive automatic.