[Alan Wheeler]

Just to add some more thought. Some of it overlaps others suggestions.
Firstly, inverters use hugew amounts of DC power. So you need good heavey cables from batteries to the inverter. The longer the run, the bigger the cable. The bigger the inverter, the bigger the cable. I have a 3KW inverter with peak ability of 6KW. I have to use 75mmsq cable to make the 4m run from battery bank to inverter. Right, so to get to my point, this means it's best to keep your inverter as close to the battery supply as possible and run the AC cable the distance across the otherside of the boat.
Next, true Sine wave is best for running your entertainment centre. These are expensive. So having two smaller ones and then one of those being able to used as a backup as well, has some merits. Then use a big modified sinewave unit to run tools. The modified sinewave units are cheap. I paid NZ$300 for a made in Taiwan type unit. It runs tools and freezers and the Microwave.

NOTE!!! Running tools maybe nice, especially if it is just a quick job. But it chews battery power real fast. So if you have a bigger job, you are going to have to start the Geny up anyway. Whether it be to run the tools or charge the batteries.

My system is set up such, that I have a selector switch on my AC/DC panel. I can switch from shore to Gen to Invert with the turn of the switch. All AC from any source is then directed into the ships AC wiring. The selector switch is such, that Phase, Nuetral and Earth are isolated from each three seperate power supply sources. Otherwise, should two differing source Phases ever come into contact, especially if it's shore power, trust me, the national grid will win the battle. If Earth and Nuetral ever get switched back to shore sources, RCD's, ELD's, GID's or what the heck every different country calls them, will trip out.