If I were you I would get an app called Remote Buddy for your Mini. With it you will be able to manage XBMC, iTunes, etc... In fact pretty well anything. They have a free trial so you can figure it out.
I mainly use a Harmony One for all my stuff. But, the Apple silver remote works fine with XBMC. I should try the white Apple remote. The only real issue with it was how to bring up that OSD which you get with a right click. I'm sure it can be done with the white remote but it's been a while.
With Remote Buddy you can launch XBMC, quit it, launch iTunes, pause or quit or change playlist or whatever, launch Plex, Safari, even use a Wii remote. It is a fantastic utility.
Lenovo makes a backlit multimedia keyboard which is very small and has a trackmouse built in. Pretty neat actually. iOGear also has a small backlit keyboard with a built in mousestick. Both work great. I prefer the Lenovo one and you can get it on sale for around $35. The iOGear one is a bit more. Neither will work with the new ATV.