Our Honda EU3000 will start & run the 13,500 btu A/C fine at sea level, even w/ the econo-throttle on.
But at high altitude (which you really dont need A/C at high altitudes) you do need it running full power to start the A/C, or it will brown out for a second until the motor can get revved up.
This is with the power converter on & charging batts, so that takes some additional juice as well.
The nice thing like said above about having 2 EU2000s is you only need to run one, until you need the extra power, then you fire the second one up. They are also light enough for 1 person to lift into the bed of the truck. The drawback, is their gas tanks are small. The EU3000 has a bigger tank and long run time. I've had mine run 24 hrs on one tank charging batteries on the trailer. It runs about 8-10 hrs running the A/C.
Either way, 2 EU2000s, or 1 EU3000, its hard to go wrong. Now if you had room & money for 2 3000s, you'd be set.
Alot of people are putting them on a furniture roller to move them around. I bought the wheel set, and rolling it around is pretty easy. Highly recommended.