Re: What cover to get
Why not get a couple of heavy duty plastic tarps from your local hardware store & some 2x4s and just get it covered really well with that for the winter? You're just trying to keep rain, snow, crud from getting into the boat over the winter so it doesn't have to be anything super fancy - just durable. Also, a heavy tarp properly tented will allow the snow to slide off much better than a fitted boat cover will (I have a boat cover & am considering a tarp for winterization). The problem with the covers is that snow will sit on top of them and stretch them, then they form pools where water sits unless you're diligent about shoveling the snow off.
A tarp solution should cost you easily less than $100 for everything - maybe even less than $50.