You can put the Kallax on wheels (castors) but that will only give you a few more inches, probably not quite enough. You can also another layer of bookshelf or something in between your board and the Kallax if you go that route (think a 6-8" wooden bookshelf you can screw/nail into the Kallax and the board above for stability. Just one idea!

Quincy134 did an LJ post on her Kallax on castors for her ironing board station and I'm doing my own version of what she made now: the Kallax and castors are delivered this Saturday and I will get a board and ironing board fabric :).

Good luck!