We can all offer our opinions but ultimately this is what it boils down to. Try as many as you can, even different scale lengths - don't be too hasty to write off basses that aren't short scale, nor ones with larger bodies.
Bear in mind most (if not all) basses on the shop wall will be wearing cheap roundwound strings, even Hofners et al, so you'll have to do a bit of mental adjustment if you're after that old-school flatwound sound.
You'll soon discover what feels right and let us know how you get on!