Novice Generator Interlock Kit Question
If you are planning to use a generator just for an emergency situation at your house. You are better of purchasing a residential type of genset. 

If you are trying to save money and only want use the generator for something other than a residential emergency supply. Then you should go with just the standard portable generator. However, your input into your residence is regulated by the 240V twist lock, which is protected by an overload and may not even be the rating of the twist lock. So you may not be getting the full KW of the genset.

Unless you have a reason for needing an inverter then there is no reason to spend the extra money on them.