Tom,

thanks for the reply!

I am having the tow bar and 2" ball installed on my 4 Runner today as I write this.
The trailer has been "commisioned" and the trailermaker is having a slow January start. No business these days! So he'll be done in about 2 weeks.
Yes, I considered ventilation on the top, and might get one of the dome vents. How watertight are the floor vents?

Meantime I spent most of yesterday planning for the electrical system. I came up with the following:

1. As you said, charging from the tow vehicle seems more like a hassle, so I am leaving out that ability. All I will have are some 12V Long jumper cables that I can run from my car's battery to the trailer, in a worst case scenario. (Either to supply car power to a small load, or to jump start my car)
2. Most of the batteries available in my country are the maintenance types, so I was thinking to go Marine -style. I will get a pair of 100 Ah 12V deep cycle gels from the boating markets here. Wired in parallel for my overestimated 200Ah consumption.
4. A Xantrex truecharge will take care of the charging of the bank.
5. From there, i will install a PERKO marine switch to turn off or on the whole system, preceeded by a filter or regulator to prevent anything more than 12v from running down the line.
6. A line from here to a pair of battery posts at the rear (inside) of the trailer, so I can hook up my sullivan hi-tork.
7. A line for the inverter, which, instead of purchasing one, I will use an existing 400 Watt monster power, enough for charging a laptop or running a dremel, etc.
8. A fuse or distribution box (still deciding whether I want fuses, (cheaper in the long run) or aviation type circuit breakers (pricey, but no need to change fuses if it is a simple overload). http://www.aircraftspruce.com/catalo...ircuitbrkr.php
9. I will have one circuit for 4 dome lights 16 LEDs each (marine too)
10. 4 10 AMP circuits to power chargers
11. 3 5 AMP circuits to power lower consumption chargers
12. One circuit for the fan
13. One or two circuits for 12V lighter plug ins
14. Grounding devices.

I will explore some of the RV stuff online, maybe I can get better deals with chargers, etc. Our local dealers have little or no RV stuff, they mostly do Marine, which offer similar 12V stuff. I also fly real planes, and will tap some of our electrician techs to helps me out with circuit breakers not good enough to be airworthy, but good enough to be trailerworthy!. The cables, and other hardware are readily available in our local versions of Home Depot or Lowe's

As soon as they have the trailer at least half-built, I will begin taking pictures and sharing