The 450's will work fine. So would the 390's or the 600's. Why? Vacuum secondary diaphragm spring selection. The 390's would run a spring with less tension and the 600's would be tightest. I'd start with the tightest and loosen up 'til it starts to bog.

Dual carbs. have a certain aura. They're just flat cool. A little harder to tune (read time consuming) but worth it in my opinion.

Hard to beat the extra cubic inches and torque the stroker motor has to offer.

I say go for it.