If you need to run anything 220 V, you will need a generator with a minimum L14-20 outlet. this is a 120/240V outlet at 20A, so doing the basic math - 240V X 20 A = 4800 watts. So your generator needs to be able to provide 4800 watts in theory. Most 5000 watt units have an L14-20 and that can be used with a transfer switch when wired correctly. Larger units will have an L14-30 that can deliver 30 A and are typically rated as 7500 watts or more. There are propane units that will deliver 20A or 30A, they just cost more (maybe not that much more). It all depends on what you want as your final goal. I hate buying something now and finding for a few bucks more I could have avoided selling it (at a loss) and then buying what I should have bought the first time.