Michael is right: if you change the sort order you will sort your premium links to the top. But there is a mistake im my previous suggestion: the <%Premium ...%> tags will only work in links.html but not in catgory.html. So what you can do is sort them to the top and mark them as premium. Other things you might want to do like deviding your premium from your normal links may be a little bit tricky.

Good luck,
Andy