Hello Douglas,
The recent ASA firewalls can support some QOS features.. you can configure class & policy maps on the ASA and prioritize traffic, with bandwidth restriction.. This is equivalent to a LLQ on IOS routers... Please refer to the following URL for the configuration in ASA:
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a008063705d.html
One thing to consider here is, even though you do QOS at your end, Once it goes to the ISP, it uses fifo. so, applying qos at your end, will not completely prioritize traffic from source to destination...
hope this helps.. all the best.. rate replies if found useful..
Raj