Yeh Perf A and "Handling the big jets". Ground courses realy pull apart the aeroplane and its performance charts, so be prepared to put in the study time. Is the course CBT or talk & chalk?
Just remember a jet is only another aeroplane. Only it just goes a hell of a lot faster and makes more bloodey noise than the King Air. Only differences to keep in mind is coffin corner, effects of sweepback, effects of mach and high altitude, dutch roll (although the 737 isnt realy a dutch-rolling bitch even with the YD inop), and that jets are realy sensitive to airspeed: ripping over the fence in the King Air 10 knots too much is no big deal. Rip over in a jet 10 knots too much and the thing will refuse to touchdown (esp if close to MLW) and chew up all your runway.
Only other thing that comes to mind is to watch out for high sink rates close to the ground. Sweptwing jets (incl all types of 737s) hate it.
The 737-200 in my opinion is ok to fly with no tendancey to give you any nasty bites if you fly it well.
PS I prefer the 200 over the 300 anyday!