This is coming from the guy who is shelling out $5K for a custom cover. I tried off the shelf, it was way too heavy, I used it once. I did a custom for the hard top and used heavy material, that was a mistake. You want fairly light weight material because, if you are old like me and you have to put it on and take it off yourself, you just won't if it is too heavy.
I'm on my 2nd custom because I went from a hard top to a custom pilot house and the old one didn't fit.
If you can't do custom, buy the lightest weight whole boat cover you can find. It will be $500-$1000 and will wear out in 5-10 years, but unless you are some young fit person, you'll thank me later. Or sooner.