* thanks for your service *
Now about the bike. Between the GS(A) and the KTM, it depends on the riding you intend to do. While both are very capable all around bikes, The BMW is more comfortable and better over long distances on the road. The KTM is a better dirt bike.
Edit: The GS is very easy to maintain. As other's have said give the regular GS a look. I was looking at both and went for the lighter weight of the GS. In my opinion the only practical advantage of the GSA is the extended range unless you are really going to do some serious off road bashing.