12 or 24 Volts?

by Bob
(Australia)

Hi all! I'm in the process (in Australia) of converting a fishing trawler to a pleasure craft and completely renewing the electrics. At the moment the boat is wired for 24v but it's much easier to get 12v stuff here. Do I switch to total 12v system with a new alternator and a series parallel switch for the starter or run a dual system with another alternator (the engine could handle two) for the 12v? Any advice, ideas etc would be most welcome