I'm another one to vote "DOB".
I would also suggest that if you can have a look at a few different sizes in person it will make a big difference. The last thing you'd want to do is buy the biggest that you fits your budget just to realise after it has arrived that it is far bigger, heavier and awkward to move around than you like.
As Glen mentioned, 10" is a great size as it does get bigger and bulkier from 12" and beyond. You may find a 16" perfectly fine or you may not, best way to find out is to find a local astro club
