unusual saltwater set up idea

Hey all

Im looking at setting up my aquaone reef 300 tank in a local saltwater set up.
Im going to go fishing and catch a few colourful leather jackets and 2 trumpeters.

My questions are, seeing as i cant find much info on the net.
1. how will i find out what temp is best to run it at for these fish? i cant seem to find anything on it
2. is the salt water for what i need here the same as any other tropical set ups you see lots of?
3. is there any starfish that would thrive with the above set up? (i know they probably arent in the same spot as where i will be getting these fish from, just always wanted one!)

Thanks