I'm very interested in this.
My travel requirements come from two directions. (1) I regularly (twice a year, sometimes for 2 weeks) find myself abroad in the same place without a bass. Not good. (2) About every a couple of years a friend organises a small festival abroad. Since I'm not always in a formal band, just jamming, I have to weigh up a whole bunch of stuff (like how much use I will get from it / value of the bass / risk of damage in transit / travel by rail or by air) to decide which bass to take. I've also done the odd gig abroad with my current band.
So far I've come up with a solution to (2) (cheap squier 5 string / SKB bass safe / total investment 125 quid) but not (1). The solution to (1) at the moment seems to be purchase of a very cheap fender (4-string) clone to permanently leave abroad as a practice (not gigging) bass.
So if you want to entrust a bass to me for a couple of weeks, I can promise to tell you how well it 'flies' . Have you considered a hard case for flying in your plans ? (One of the reasons I've gone for fenderish basses is the ready availability of 'lite-flite' cases and the like). If you're producing a short scale bass presumably you'll need a custom case ?
Noticed an earlier discussion on strings, and you said you'd be using standard strings I think. Does that mean you're going for a standard short-scale bass speaking length of 30 inches ? I ask because I have experienced string breakage from winding 34 inch scale strings onto the tuners of a 30.5 scale bass. The fat bit does not like going round the tuner, certainly on flatwounds. One solution to this of course, if you're going shorter than 30 inches, is to accommodate the extra string length somehow at the other end, e.g. through-body stringing.
Very interested to see what you come up with.
Andy