[eluser]sophistry[/eluser]
be aware that in constructing models you are building a mini API for your application to access your db tables.
with that in mind, i would caution you against returning an array with the FOUND_ROWS() count and the LIMITed array stuffed together - it's just not a good design IMHO.
better overall API-minded approach would be to:
create another model function that can run FOUND_ROWS() and return the count. that keeps the FOUND_ROWS() call decoupled and available to other model functions should you need to use it down the road.
just have to make sure that you access it in the next line $this->themodel->get_found_rows();
cheers.