With any length to the catintro section, the Per Page / Sort Options row in cathead.tmpl makes more sense in the categoryX.tmpl file, just above the categories. It may make sense to consider hanging this row on top of the categories instead of at the bottom of cathead.tmpl.
Here is an exmple of a timeshare auction
category with a lengthy catintro. The sort row has already been shifted according to this suggestion.