FlyX has some good points for you, but missed one important one.

With the sim, if it crashes all you have to do is hit the red button....

The sim will help you build reflexes and correct control operation, but it's quite different with the actual model in the air and as he pointed out, landing will be the most challenging difference.

I would not suggest you try it on your own with your current experience level and only the sim experience. If you're dead set on a Mustang, I'd suggest you get yourself a Hangar 9 Mustang PTS before you try flying the Top Flite.

It comes as either RTF:

http://www.horizonhobby.com/Products...ProdID=HAN2825

Or as an ARF:

http://www.horizonhobby.com/Products...ProdID=HAN2845