If you enable the IR remote, your an practically use any remote to pause, play, next and back functions, otherwise you can look at VNC/Remote Desktop solutions on any device like an android or iphone/ipod touch. Logitech has the IR codes. Of course you can use Apple's "screen share" to have your laptop view the desktop of your mac mini.
I would probably encourage you to look for an old iPod touch, the remote app works on all versions of the hardware, and honestly I don't think you can find a better remote for iTunes than that and that works on Macs or Windows.