Depends on your application. If you want water tight and UV protection (for the cover) you'll spend more.
Do you want to be able to lock the cover with a cable underneath?
If you just want dust protection inside the garage you might consider just using old sheets.
If you have little ones that like to make dents with their big wheels, you'll need some padding.
Determine your needs then you can shop.
Keep in mind that any cover you put on the car is likely to inflict scratches, even minor, with repeated use.
I've owned many car covers.In my opinion, the best covers are the ones I own right now. They are a nylon outer shell with a felt liner. The liner does a great job of keeping the paint from getting scratched. Thet have elastic banding around the bottom and grommet holes for tying them down. I am not sure of the brand name as they were given to me as a gift. I'm sure they are not cheap, but anything that protects your stang is an investment.
Also, don't forget to get the one with the zipper at the drivers door so you can get in the car if you need to.
I bought a cover similar to plushweave, but bought it from MU.
The heavy felt underpadding cushions the car from minor bumps. My 68 has new paint and garage kept like yours and the cover seems to keep it clean safe.