I used steel shelving that I accessed from "Storables", a US chain store, to construct a roll-able cart for my Omega D6. They will cut the posts to order without charge, so you can customize the height.

I went this route because:

1) The enlarger is heavy (especially the baseboard!). The cart is, necessarily, strong!;
2) The baseboard is 18" x 34", so I needed a cart big enough to hold the whole thing;
3) I need to be able to roll the cart plus enlarger through a normal bathroom door. As the enlarger has an extended column, I needed a cart that is only 21" in height.

The steel shelving plus castors cost me just over $100.00 USD. I needed an additional piece of 1/2" plywood as well, on the top.

It will probably outlast me .

Here is a link to the Storables website:

http://www.storables.com/Shop/Shelving/Steel-Shelving/