The early blocks are generally considered stronger then the later roller blocks. If you're planning of stroking and using a power adder I'd go for the early block. Bepending on the sort of power you plan on making, it might be a good plan to start with an aftermarket block.
A set of drop-in linked lifters will allow you to use any standard base circle roller cam in your early block. The linked lifters are expensive, but imo the only way to go when using an early block.