I have a 5'er with an onan 5500 LP it works great and powers both AC's.
When its hot out both A/C's are required to cool my rig.
If you choose not to go with the Onan but use portables it gets more complicated.
What kind of plug does the genset have? Does it have a 50 amp RV plug?
How are you going to move the larger heavier models. How are you going to transpoet and store gas. Is the plan to use genset 24/7? Are there others nearby to contend with genset noise?
Back in 2012 I factory ordered my unit with a genset however if I were doing it today I would invest in a A/C capable solar set up and skip the large genset. Times have changed.
