IMHO there are 2 things you need to consider, besides price. The first being noise, there is no doubt that an inverter generator will be much, much quieter. If you plan to run AC overnight that is big consideration. The second thing is how long it will run. If you're planning on running the AC overnight you will probably want a 3000W size with a large enough tank to run all night. You don't want to have to get up in the middle of the night to refill the gas tanks. You can get extended run fuel tank set ups for running smaller generators in parallel but for me that's a bit of a hassle.
I have the Honda eu3000 it has a 3.4 gallon tank and will easily run the AC all night during the hottest part of the summer in Arizona. I've no experience with any of the other popular brands like Yamaha or Champion, I'm sure they would work fine. Just check the gas tank size so you know how many hours you can get out of a tank.