You should be able to, get a cooler and a DC inverter to run a pump and a heater or possibly a chiller. You can get the water from the ocean. You will need to look at getting permits as john said. If you find any info out let me know I am also a diver that at some point would like to do the same thing. (as long as its enviromentaly ok). Also one of the ways to get inexpensive corals is to join a reef club, members in our club like swapping frags or selling their frags inexpensively.