You'll want to stay small if you're going to be freeway cruising with 3.23 gears. If the cam is too big then you'll just suck up the gas going down the highway since the engine will be inefficient at cruising RPM.

I'd use the Comp hyd roller if you're willing to spend the money on the lifters and the correct springs to run it. That old Isky might work. Personally if it was my engine I'd use the Mopar .528 solid flat tappet. The MP .528 works really well for street driver stroker engines with tall rear end gears.