Engine Decision?

I have the choice of building a SB350 or a SB400. Which one
be more worth my time and money. Would it be better to just build a 350 or put the 400 crank in the 350 and bore the 350 .030" over to achieve a 383 stroker. Or would it be better to just build the 400, the 400 has siamesed cylinders and will run hotter, is that going to be a problem? If I were to put the 400 crank and rods in the 350 block, would I have to do anything with the heads to keep the compression at a decent ratio, probably around 10:1 to 11.25:1. The stroker motor would lower my ability to achieve higher RPM's, so with the additional torque, would I have to make my gearing higher in the axle. Which of the three motors has the most potential for decent tourqe, but still be able to acheive high RPM horsepower? Which would also acheive the best fuel efficiency? I don't want to spend a fortune and it will be a high performance street rather than a drag motor. I would like a moderatly lopey idle and have power from 1500 or so RPM's to 6500 or so RPM's. Any help would be much apreciated, thank you.

If you wanted to put the 400 crank in the 350 i believe you'd have to get the crank ground down abit to fit into the 350's main journals.