Check with you closest Bennington dealer to see if their covers still available for a 8 year old boat. Bass Pro Shop and Overton's sell universal boat covers, and covers can also be purchased on the internet.
I'm a proponent of using factory snap on covers to protect my investment--even if they're $800. They're worth it, because they'll keep you from having to prematurely replace your carpets and vinyl seat covers--and replace rotted plywood decks.
If unavailable, see if your local awning shop or upholstery shop can whip one up for you using your old cover as a template. You may even save some $.