There are some good ideas here but also some of you are making this way to hard. Go ahead and use an apartment model refrigerator. They use less power, are bigger, and work better than RV refers. The standard unit will stay cold for a long time if you leave the door closed. My parents have had them in 3 bus conversions and no trouble with it warming up while traveling. Absorbtion refers don't work as good in very hot weather. For cooking get a microwave, a toaster oven for the ocasional baking, and a portable 110V induction cooktop. Dad uses an standard 10gal 110V water heater like you would find in an office, him and mom take regular length showers, one after the other, without running out of hot water. Your regular 12V water pump will provide adequate pressure. Use a standard RV toilet. Someone said that the gray water should be 3X bigger than black. I will agree with them. My toter has equal tanks. The gray water fills up while the black barely has anything. You can use a single tank for both with no problems if you want. They use very little water and serve the purpose just fine. For heating and cooling go with a minisplit system. These are heat pumps so they provide heating and cooling and are much more efficient than than space heaters. They even make dual zone units if you want to heat/cool the workshop separately. Look at minisplitshop.com for ideas. Used stranded wire in you conversion because solid wire tends to break with the vibration caused by driving down the road. I think that you can get away without an inverter. Do you really need 110V while moving? You can use 110V lighting but make sure to have a couple of 12V lights so that you can see what you are doing while not plugged in. Make sure that your generator is properly installed and vented. Carbon monoxide kills. Put CO detector in your rig. You can use household sinks, faucets, shower..... You mentioned a bathroom sink and a kitchen sink. Think about putting a utility sink in the workshop. Its very hard to wash your hands and arms in a tiny bathroom sink. I work on big dirty stuff and I'm always dirty all the way up to my elbows. Maybe an outside faucet would be handy also.
