If you really mean "surge protection", then the Leviton R000-51110-SRG whole-house surge suppressor is hard to beat:
It has better specs than the RV-specific ones and is far cheaper. Plus, it is designed to protect both legs of a residential feed, so you have a built-in spare.
If you also want other protection, such as checks for polarity, ground, frequency, and/or voltage, then you should first check to see what your inverter/charger does. Many of them have such checks built-in, in which case a surge-suppressor is all you need. If not, then one of the expensive RV units might be justified. Depends on where you camp.
In my case, our Outback inverter/charger does sophisticated testing, so I went with just the Leviton unit plus a Bluesea 8077 circuit breaker (which also checks polarity):
control panel 2.JPG