The size of the trailer doesn't matter. It's the number of watts that you consume at any one moment of time that determines the size of the generator.

Count up the electric items you use in your trailer.  Consider which devices you have on at the same time.

For example.  An A/C unit usually needs around 1800-2000 watts to start up, A blow dryer for your hair is usually 1200 watts. If you want to run both devices at the same time you would need 3200 watts.  You need a generator large enough to power ALL the devices that you will run at the same time.

I have a Yamaha EF2400.  It will produce peak power of 2400 watts and contineous power of 2000watts.  I can run my A/C unit with this generator. But I can not run my A/C and Microwave at the same time.

As far as brands,  Pick one that makes a Quite generator.  Nobody likes to camp next to a noisy generator. Look for something around 52-55 decibles.

Honda and Yamaha both have models of generators based on  Invertors.  These will give you a cleaner sine wave. Which is important if you want to run high tech electronics, like laptop computers. But these generators cost more and usually don't produce the larger power.  (1000 to 3000 watts),  But you can connect two of these units to produce double the output.  Two 2000watt connected produce 4000 watts.  Two 50lb generators are easier to carry than one 150lb unit.  Light bulbs, Hair blowers, heat strips, stove burners are all low tech. They don't have electronic circuits that can easliy be burned up. They have filiments or elements that heat up when electricity passes through them. The resistence produces heat or light. Any generator can power those type of devices. It's the high tech devices that need the clean power. Remember that a computer chip circuit can be thiner than a human hair. Too big a surge of electricity and it's toast.

There was a recent thread about the Kipor brand of generator. Very low cost. Produces adequet electricity for a trailer and was reasonably quite. I don't know, but suspect it's not an invertor based generator. That said, it's probably a good unit for running light blubs, heating hot water in an electric water heater, running a compressor for your A/C etc. But it's probably hard on high tech circuits like lap top computers, DVD players, Flat panel TV screens etc.

Consider what you need to power in your trailer. What other uses you may use a generator for around the home, How heavy a unit you can pick up and move, How large a unit you can store in your trailer/truck. And of course your buget.  Do a google search for generators. Several sites will pop up that have very good mail order pricing.

The Kipor 3500ti does have inverter technology.

Mike

Yep.  The yellow TI model has inverter technology.
not the red the TC.
I have a Philips LCD TV and DVD in my trailer and they work flawlessly.