Jon,
It is all IFR in the sense that you're using the instruments as reference rather than visual (but you're certainly not doing NDB holds or anything). You get talked through everything very clearly. If you are able to take in what you are told and learn reasonably quickly you will pass. If you have no flying experience they will account for that. There's plenty of info on stage 4 if you read every page of this thread (that is if you have about a week to spare!!!).
Good luck
ps, as for the sim you use, i imagine its just whichever one is not in use at the time