There are two exceptional sims; one is Great Planes "Real Flight", available from Tower Hobbies and cost about $200; the second is a sim called "Aerofly Pro". I don't know where to buy Aerofly, or how much it costs, but I believe the cost is a bit less than RF.

FMS is a free simulator, but it doesn't have adjustable parameters like wind speed, or the ability to change engines or control throws in the planes. To use FMS you would need to get an interface cable off the internet to connect your transmitter to your PC. (The other two come with a "box", or fake transmitter.) The interfaces for FMS can be purchased for about $25 shipped. Do a search for Matt Clements.
Dennis-