I'm glad you took my comments above in the spirit they were intended. You are contemplating a trip of far outside average proportions and while it is doable and could be a terrific adventure it is also well within the parameters for misery and discomfort to be unwelcome and constant travel companions. I'd suggest doing as much research as you can and certainly don't leave out the pedal bicycle touring sites, in a very real sense you'll find more specific info there about touring and routes than the motor biking sites. One among many is:
America's Bicycle Travel Inspiration & Resource - Adventure Cycling Association
And then there's this guy:
http://thirstybike.org/, 15,000 mile trip planned with a Robin35 and Staton shift kit
Average putting around motorized biking is one thing, pedal bicycle touring is another.
Motorized bike touring is different still and an endeavor in large part unexplored with not of a lot of solid, experienced, info to go around.
I mention this because much of the info or advice garnered off of the web will pertain to areas of interest that you have adapt to your own needs. Generally motored bikes are made with little concern about how they pedal, are heavy, many are concerned only with how fast they'll go and they are often constrained by constant tinkering and parts failure and thus most don't put many sustained miles on them in a continuous run like in touring. They are used primarily for putting around locally within striking distance of home base for fixing when needed. Heading out on the open road is another matter.
The folks I know who do self-contained distance motorized bicycle touring don't seem to frequent the forums much but the best piece of advice I've seen lately came from
WileyDavis who does extreme touring and does comes around on occasion:
Best piece of advice you can get right there and it's good that it seems to fit your outlook as I read you mention pedaling cadence. Too many I believe think unrealistically that a motorized bicycle is going to do it all for them.
Get a bike that you are comfortable on, one that is both fits you and you like to pedal because that's the basic idea with a self-contained touring motorized bicycle. If not a small motorcycle or scooter would be a better bet.
More random thoughts for further conversation and dialog in no particular order
Weight is the enemy of the distance tourer. Consider well what you can do and do without. Saving a few ounces here, a pound there adds up because ultimately it becomes a power to weight ratio equation. If you have belongings you want but won't need on the trip until the other end, consider shipping them freight.
I've done thousands of miles of pedal bicycle touring and more recently over past 4 years gotten into power assisted bikes. We did a tour on motorized bicycles on the coast of Maine this summer, 380 miles one way planned route, ended up a bit over 800 miles round trip with side travel.
Wheels, can't say enough about it and the first thing I would say is invest in good wheels with adequate gauge spokes with quality hubs and maintain them meticulously, I had a bearing race go bad on a rear wheel this trip because I didn't.
Tires and tubes, use the best you can afford. I also use tire liners and thorn proof tubes. 800 miles and no flats, a first.
Trailer, don't know what you have in mind but I love the single wheel I have. It's the Bob style knock-off from Nashbar I picked up used for $50 and reworked the hitch it and swapped out the wheel with an upgrade. A trailer flag is a pretty darn good addition.
Fuel is heavy, depending how well planned your route and daily mileage will determine how much you need to carry and what size tank(s).
Lighting. There's no end what you can spend on quality bicycle lighting but minimum for daytime travel I wouldn't go without a multi-mode red in the rear and white nano strobe in front. If you are going to do ANY night riding then serious upgrades need to be considered.
A center kickstand is a great asset on a touring bike, especially with cargo.
Travel tools. There are some adequate multi-tools though generally I don't care for them. They are convenient without a lot of weight but still I prefer to put together my own minimalist kit with a eye toward size and weight but that do just about anything on a bike up to complete overhaul.
One further thought before I forget it.....though I like friction drives for many uses I have been of the mind they weren't the best for touring. The chances of encountering wet weather in some locales doing extended touring is high. The inverse of that is long days of hot weather which can speed tire wear and transfer a lot of heat to bearings and engine crankshaft. That said, it should be noted that one of the long ride guys I mentioned above who doesn't frequent forums much has, for himself anyway, certainly put some of that to rest. He's done mega tours up the continental divide (in obvious dry climates) from New Mexico to Idaho and back on a friction drive/Robin 35 bike (no trailer) and had a great time with it.
Best of luck and ride safe.
