Another good "FREE" sim is PRE-FLIGHT more realistic than FMS as far as Heli's, as far as an interface there's some out there for PRE-FLIGHT. for me I went with a game pad with 2 analog sticks like the Logitech one or an interact axis pad to simulate a radio control (cheaper than an interface)
http://www.preflightsim.com/ here's the site, check it out