That large Anthro keyboard, mousing, wacom shelf sure is nice to use. Very easy to adjust from sitting to standing. When I commited to making an OSHA approved work station 2 years ago all my Back problems and Carpal Tunnel problems went away. There are not any alternatives to Anthro that I've seen. Maybe one of the vertical magliners they use as a video cart in the film industry would fit you needs:http://cinemasupplies.stores.yahoo.net/filversounan.html
Very customizable. Very mobile
I've seen this cart in action, but with a VESA arm for the monitor. Sort of a mini-mini magliner:http://www.imagemechanics.com/site/Capture.html
good luck. once you get the computer cart races going in your studio post a picture for us.