In the end, action height is something you will decide only by trying basses with differing actions. Many players on here will tell you to get the action as low as possible but it's horses for courses. I never liked a really low action as I find it more difficult to play, also I am slowly using a higher action as I (subjectively) prefer the variability of tone that it seems to produce.
Whereabouts are you @drummerdave? There are lots of excellent luthiers dotted around the country, we can probably recommend one nearby.