Thanks for the reply Dana. No, a view-all page is not an option, some of the categories have over 11,000 items - so we can rule that out!
I've looked at all of the existing resources, and while all of them offer great advice, nothing touches on the subject of multiple sort options - they seem to be only for standard page 1, page 2... etc listings.
The link you provided to the YouMoz post we have read through thoroughly and they do it a little differently. In their example, they sort the items on the current page, while our sort options would change the order of the entire category, therefore we can't use canonical... as the page content is 100% different.
We want to work with multiple sort options and wanted to know the best way to do this.