you like the set up?
could it work for five?

I have the Sun-Mar Excels, two of them. They have the heaters and a 2" exhaust stacks. No fuss or oder. Just empty a harmless black compost out around my trees once a week or so. My greywater system consists of 2 55 gallon barrels sunk into the ground with one inch holes drilled in them and filled with rocks. My greywater system has been in place for about 5 years and has not given me any problems.
At first with the composting toilets it was a little strange not flushing after use, now we don't think to much about it. I bought the Excels because my house has a tendency to get a little cool in the wintertime and if you let the toilets get too cold the microbial action shuts down in the composting chamber. You can get Non-electric models that are rated at 2-3 fulltime users, these have a 4" exhaust stack, but your house needs to stay above 70 degrees.

By taking toilets out of the water usage loop my household water usage is under 200 gallons per week, we have low flow nozzles on all our faucets. Use the sinks instead of letting the water flow when we wash dishes. I have 150 gallon water catchment on my downspouts I use to water the animals and the garden.

I have a berkey thet we use for household drinking and cooking, nice piece of equipment.

Shop around for the Sun-Mars I found a lot of price difference on the internet, I eventually found factory blems for about half price.