Hey Cfendrich,
There are a few things to consider here;
1) How big is your AC unit? A 3000watt inverter generator will power a 13,500 BTU AC unit and anything smaller. If your AC unit is 15,000 BTU's you should go larger than 3000watts.
2) NOISE: No one wants their campsite to sound like a construction zone. If you are looking for quiet portable power you are in the market for an INVERTER generator (as opposed to a conventional generator). Inverters also produce a "cleaner" power source that is suitable for sensitive electronics such as laptops and smartphones. The inverting process produces a smoother sine wave that will not damage the microprocessors within these electronics.
Many people swear by Honda's and Yamaha's and they are the industry leaders when it comes to inverter generators BUT there are many alternative companies (ie Champion, WEN, Westinghouse) putting forth very competitive products at a lesser price that merit consideration when shopping around for a generator.
I found this website to be extremely helpful when deciding which generator best suits your needs;
quietpowergenerators.com
The "inverters vs generators" page is very insightful and arms you with the knowledge necessary to make an educated purchase. They also have a "usage charts" page which helps you calculate what size generator you will need for your particular electrical needs. It also has detailed reviews of the latest and best selling inverter generators on the market.
I hope this helps! Happy camping and all the best,
Dave