Agree with KMP44; very nice summary.
I am not familiar with all of the available Zamp systems, but I would be thinking 150 watts minimum. The panel capacity has improved since we got two panels for a total of about 180 watt capacity.
I found this tool helpful to calculate capacity requirements. Note the furnace use is the big capacity DC draw; maybe not an issue in your area but huge in the Great White North.
The pump is only run occasionally as you will probably run out of holding tank capacity before the power usage is a monumental issue; my guess is the pump can use all of the available tank capacity in about an hour or two? Your fridge is propane, so don't fill in the 12 v fridge item. The AC loads are zero unless you install the highlighted inverter
Agree that an upgrade to two 6 volt golf cart batteries and LED bulbs for everything is an excellent idea, and should probably be considered part of the deal.
As a rough idea of required capacity, with 180 watts and two six volt batteries we never worried about power consumption when dry camping for up to four days.
Can't comment specifically on the Zamp portable systems, but understand the quality and convenience are very good, cost maybe not so much.
We have our Go Power
panels permanently installed on the trailer roof (actually, this is the second unit they have been on; we moved them from our old trailer). This is a preferable set-up for us. Any more stuff to pack in the trailer interior was a non-starter. We are generally camping at dog shows in the middle of an open field though. As mentioned, the trade-off is less performance in shaded sites, but we can live with that minor limitation. Obviously not an issue at a powered site.
Permanent installation is not really that big a deal. Both times I had the work done by a mobile RV technician for about $500. Having watched the process I could easily do it myself, although my DW may not share my confidence.
The Roo 233S was particularly easy as the main power equipment is conveniently located below the fridge, which is where the wires from the roof are routed. A permanently installed system of similar capacity may be cost competitive with the Zamp portable, so you may want to consider as an option?
We did not install an inverter
, which is the required hardware if you want any 120 v AC plugs or appliances to work. If you really want this functionality a high capacity permanent system with professional installation and the mentioned large battery bank (four six volt golf cart batteries) is probably the way to go. I have since mounted this larger battery bank on our 233S, but not familiar with the available room on your unit. We are/were debating adding an inverter
to our system, but for our usage it is really not a requirement. My wife has to run a generator periodically anyway to blow dry the dogs for the show ring, so we upgraded to higher capacity generation and may try it for any occasional microwave use.
The tagged Carmanah Go Power
site has a good description of the various recommended systems (capacities and functionality) to get you up to speed. The Go Power products are widely available and good quality, although I am sure there are similar providers out there.