Reply to New DJ set up?

Hey everyone. I'm an intermediate DJ looking to upgrade my setup. Currently I am using the Numark Mixdeck Quad with Djay for the Ipad 2 and sometimes laptop with serato intro. I'm looking to get some new gear to take my performance to the next level. What gear should I get that works with the stuff I already have? Or should I renovate and get some new gear entirely?