The xs' boats are running well over 100. One is closing in on 110, I personally can't see the 24 being that fast, but again. Mark is and has been right every time on his estimates.
So let's assume, the 24 should push 100 with a single outboard. As far as sterndrives. I'd run the illmor long before I bought a 600 from mercury. The only plus to mercury is that is is very easily upgrade able.

