I believe the optimum current motors for those hulls would be the Etec 130, and the Optimax 125. Both about 375 lbs and plenty of guts to get you low 40s WOT and 4-5 mpg @ 28-30 mph cruise.
The Smokin' motor would be a mid-late 80s Merc 175hp 2.4L weighing in at about 360lbs