I don't think, that the LHD/RHD-conversion is a good idea. At least it's cobbling around. The Mustang is -like all US-cars and non-British European cars- constructed as LHD.
What do you mean with "easier for me"? Do you are anxious to drive LHD? I'm sure, it's easier and cheaper to learn this, than to convert a car.
O.k., it will be uncomfortable at parking-garages and Mc Donald's Drive Thru - but the last thing isn't a problem for you, because now you don't have to use this lane...
And not to forget: if you let the car as LHD, it will be in original, "classic" condition. So this will be much more stylish and "cooler". Surely the girls will think it, too.
And driving LHD is more comfortable. At the most cars the space for the legs is bigger on the left than on the right side.