Portfolio Sorting

Hi there,
I have a couple of question relating to this.

I have 9 portfolio categories, if I choose to display all portfolio categories, but restrict the number of displayed portfolio items on this page to, say, 18 – not all of the portfolio categories appear in the sorting/filter menu.
I understand why this is happening, but how can I display *all* portfolio categories in the filter/sorting menu – even if no portfolio items appear from all categories on initial page load?

This is a little trickier. I have a client who is a designer, they want this portfolio/sorting menu to appear on an individual portfolio post, on its own, in a specific location on the page (the very top).
Is there any way I can find the code that generates this sorting/filter menu, & add it to this individual portfolio post – on its own?
I’m guessing there is a bit of php in a template that displays this, if I could add that to the sing-portfolio template, that’d be super cool.

Thanks,
Jason