Edit Default Sorting Method on Products Category Page

I am using MarketPress in conjunction with CoursePress. I have some products to sell that are not courses. I would like to edit the default sorting method for the products category page. Specifically, it is first showing with a default sort method of Name (Z-A) and I would prefer that the sort be by Name (A-Z).

I would also like to reverse the sorting method for related products when listed beneath the item.