Andytoad - tone is such an illusive quality that if you think you have found it with an SG type bass then nab it! Size of bass - who cares? I posted this before but check out Hamish Stuart, not a small man and a bit of a geezer by all accounts, playing a Mustang. No-one appears to pointing and laughing.
http://youtu.be/qSP5yiUbDLQ
I am not small - 5'10" and 100 kgs - I regularly play a Musicmaster and have just recently acquired a Danelectro Longhorn, both shortscale. The Dano is ridiculously camp, frankly, but I am not remotely bothered.