I would not let the balance issue stop you. I am old enough to remember straps attached to headstocks. A long horn gives you a lot of places to put the strap button. It may be just fine on the end of the horn, but if not you can put it somewhere else.
On the upside you'll have a totally unique instrument that won't look like anyone elses. I think it could work pretty well with something like an un-routed IB-5 body, which has a rounder heel than the Yamaha. Degree of difficulty shouldn't be too much higher than any other un-routed body.