Be certain to obtain a "binder" before moving it off the dealer's lot. The most likely time to damage it will be in your early ownership period. (A low deductible that first year might be an attractive option.)
I'm a "Good Sam" member and they pepper me with ads promoting their insurance. When I called them, the answering party first appeared to be a partner in the Good Sam Club ...but upon questioning, it became apparent my call simply "rolls-over" to subscribing insurance agency. A return call apparently rolled over to yet a different agency. I.E., I came to the conclusion Good Sam merely earns a referral-commission, it's a marketing scheme and despite their ads, they offer little if anything more than my auto insurance agency could offer.
So I'm insured with State Farm and have had good experiences with them over the last 39 years.
Just be aware that there's a difference in towing, roadside assistance (not likely anything you'll need since you don't have a motorhome) are not worth addt'l premiums, in many cases. (My auto policy regularly covers towing...including any "trailer"...so no need for me to buy a travel-trailer-specific towing policy.)
Good Sam offers "stored" deducts if you don't use it for part of the year, but so will many other policies. Beware that if you store your AS at a facility that if they move it and damage it your policy may not cover it, so you'll want to inquire about the storage facility's policy and insurance.
One thing you'll also want to check is "replacement vs declared" value should it be "totaled". Good Sam (and others) will buy you a new, comparable unit if your's is less than 5 years old. Otherwise, be certain of your underwriter's definitions on those terms.
In any case, you will want to shop around and compare.