An F4 would give you the high shutter speeds, along with a 100% viewinder, but it's big and heavy. Newer models like the N8008s, the N90s, and the F100 give you great capability with high shutter speeds, and are proven reliable, also. The N8008s and N90S are really dirt cheap these days. I don't have a problem focusing manually with these AF cameras, but if it is a problem, you can get an aftermarket screen.