Not a generator/electrician but you will be drawing max power out of both if you need 6000+ which is not good. Also how would you ensure that both are feeding equally?
Years ago I picked up one from these guys. At the time great prices and free shipping. Just be sure you have enough startup power/running power to cover your big items. Mine can power my whole house less the A.C. and the oven but don't need that in an emergency.
Portable Generators