Some posters report that a Honda 2000i will - or "almost will" - under certain conditions run their rooftop 13.5K A/C.
This tells me that the Honda 2000i should run an 8K A/C easily under all conditions... and probably an 11K A/C easily, too.
Also, all air conditioners of any given capacity are not the same. New high efficiency 13.5K air conditioners will probably run pretty good off a Honda 2000i.
Are the 8K and 11K air conditioners of the older design - or do they use high efficiency technology? I wouldn't buy any new RV air conditioner of any capacity unless it was the high efficiency type. You can't have too much air conditioning in an RV - but it should always nowadays be high efficiency, IMHO.