My father in law lives on Cape Cod with in walking distance to the beach. His grill sit out on the deck year round, it has never been covered - that would impact his ability to cook a hotdog in middle of winter if he so wished. He has over time replaced various parts as they wear out or rust, bit like the flavor bar (thinish steel triangle bit righ over the flames and right under the dripping grease), the grill surface (cast iron ) and the ignitor.
Recently, after 10+ years, he replaced it, not because it was broken, but his daughter was getting married and he wanted a nicer one for when guest where over - either that or he was spending enough on the wedding and dammit he was going to get something out of it! Plus it provided an opportunity to upgraded to a bigger grill. He scavenged it for spare parts which he passed to me as I had an identical one, but purchased 5 years later.

His 10+ year old grill, for which spares can still be purchased, was a Weber Genesis(?) Silver. I might have the exact model wrong, but it was a two burner. He moved up to a three burner model with a silver top to it - not sure what model.

Given how well his original stood up to the salt air and the availability of parts I would strongly recommend a Weber.
As for switching propane tanks, either buy a spare tank or swipe you neighbor's