I had the same problem with my Origin2000, again a rack module I bought the deskside skins for from dexter1 (who is a superstar!). I built a wooden plinth for it that allows good air flow and allows it to move pretty easily on my wooden floor. I also has the benefit that you can screw the bottom of the plastics to the bottom of it which makes it much more solid than relying on the age old plastic catches which seem to break off if I even look at them! ;o)
I'll draw you a diagram of the design and send it if you are interested. The wood I used as this:http://www.wickes.co.uk/Wickes-Studwork ... e/p/107713
The height when standing edge on is just right to give it good clearance and when layed flat can be used as the cross members which allows air to flow through. Works very well, my stacked Origin 2000 has run happily for hours on this.
I must confess though like you I do want the proper base and wheels! ;o)
Hope this helps anyway,