Using Specific Shipping Method For Different Product Types

I have an online bookstore running on the latest version of OpenCart. Previously, I used only one shipping method (USPS media Mail for US purchases) since I was selling only books. Now I want to branch out and start selling other products, such as toys.

USPS media mail is cheaper than USPS parcel post, but this option can only be used for books or dvds. If I enabled USPS parcel post, customers have the option of choosing which of the two shipping methods they want at checkout. I do not want this, as if a customer is buying only toys they are not eligible for media mail. Also, if a customer buys a combination of books and toys, I would like to either default to USPS parcel post or UPS.

Is there an extension that allows me to automatically specify which shipping method to use per product type? I don't know if it's relevant, but here's my website: http://sffoutlet.com/beta/

Thanks for your time.

Qphoria offers a Shipping By Product module.