Let's see...selling a sport bike and a KLR to be replaced with one bike. I think I'd go with a KTM690 and the spare wheels you mention. Unless your sportbike is a POS, you should get a few bucks for that thing as well as the KLR. You put all of that toward the KTM which is one of the few bikes in the world that can actually do some decent off road and provide some pavement excitement too. The 690 would kill a KLR in any off road or pavement situation, and on pavement it has the power and handling to satisfy quite well...especially with the extra wheels and tires. And later when you can once again afford two or more bikes, I'd almost bet you'd still keep the 690.