Inverter type generator are much better overall, and in this case well worth the extra money. Inverters are much quieter, cleaner power and more fuel efficient.
IMO you should get the 2800/3100 inverter, but get it from Costco.
2007 Chevy Duramax LMM/Allison
2012 Jay Flight 29QBH
2012 Jay Flight 26BH (Sold)