I'll second what Airventure says above. Good instrument skills are a must and learn as much about FMS systems as possible before you get there. However, don't feel like you're at a disadvantage. I've witnessed several experienced pilots transition into an FMS equipped aircraft from steam gauges and struggle mightily. They're unbelievably good at the stick and rudder, but scared to death of today's automation. Even a little experience with the GPS systems in newer light aircraft will go long way in helping you. I'm not familiar with SimuFlite's program, but every training facility usually has an avionics/FMS guru. Find that person, latch on, and pick their brain as much as humanly possible.