The two main players in RV surge protection / EMS are
Technology Research (TRC) and
Progressive Industries which each offer portable surge protectors and surge protector / EMS units in portable and hard wire configurations. Having owned a TRC Surge Guard and TRC Voltage Regulator myself I understand the drawback in owning
any TRC product that is covered by just a one year
limited warranty from a manufacturer that refuses to offer replacement parts after that one year warranty expires. Compare that to the lifetime warranty Progressive Industries provides with the purchase of it's products and the answer IMO should be evident as to where your $$$ are best spent.
The OP needs to decide if he really wants just surge protection or whether his needs would be better served by a surge protection / EMS device that will also protect his rig from a variety of power source anomalies. The answer to this for me is also obvious - a full featured EMS, whether portable (for convenience of use) or hard wire that once installed needs no attention at all. I chose the latter and countless incidents since with source power when we're camping AND when my trailer is parked here at the house have convinced me I'd
never ever plug in again without the benefit of protecting my rig's electrical system with my Progressive EMS-HW30C. :B