Ron hit the nail on the head - you have to shop and compare to see what works best for your personal circumstances. Rates and coverages can vary tremendously, based on factors that may not be immediately obvious to you.
As for coverage, what sort of RV do you have and will you continue to carry home owners or renter's insurance while you own the RV? The type of RV is important because some insurers treat motorhomes as large, expensive cars without any "home" aspect. Similarly for trailer, where they may be treated like a utility trailer rather than a homeon wheels. Big difference in the fine print. Other insurances have a major effect on what liability and personal property coverages you need and what they will cost. Talk to the Foremost agent about things like wind-damaged awnings, roof leaks, the extensive personal property you have onboard, what happens when somebody gets injured on your campsite (not in the RV), etc. All these things have to be treated more like a home/apartment policy then a typical automotive policy. See if Foremost has a policy specially tailored to RVs.
We use Foremost to insure the dwelling at our home base (a manufactured home) and are satisfied, though we have never made a claim. I have no idea how they handle Rvs, though. We use National Interstate for the RV and get it through their in-house RV specialist agency, Explorer RV.