Hi,
I would have to agree with Erick, that one here on IIS seems the closest to ideal. I made an effort to keep under $400 the ones I was referring to, but if you can go to the little extra money I believe you will not be disappointed. It will not have the portability problems a solid tube dob has.
Reviews of the 12" model here
http://www.iceinspace.com.au/41-531-0-0-1-0.html
http://www.cloudynights.com/item.php?item_id=1920
Cheers