Well, with all that I have heard about power surges, etc., I decided to purchase the Progressive Industries PT50C (in-line) EMS. Although I may already have one built in, but that's another story.
So, I search for many different key words and it brought me to this one particular web site,
RVUpgrades.com. Especially since it was a lot less $$ than most sites. So I order it.
In short order I had an email confirming the order, but indicating it was not in stock but was expected, and the date that it would be shipped. I replied that I needed it no later than such and such date, and again received a prompt reply that I would have it in time for my trip.
I was impressed by the price, and especially the service. So if you are in the market for something new and don't know where to look, try
RVUpgrades.com.