[Festus2]

I would have thought that your 5000w generator would have been sufficient to run both A/C's providing you are not using other items like your microwave, H/W heater, fridge on AC, and other appliances at the same time. You didn't specify the BTU's of your A/C's whether they were 13k or 15k each. If the circuit breaker is tripping, try switching the fridge and HW heater to propane to see if that makes any difference.
A 7500w will be able to do both A/C's with some room to spare. As mentioned above, you will definitely be able to hear it running!