Thought I would give you guys an update. Finally I'm finished constructing the trolly and mounting the Durst. My plan worked out really, really great. The trolly is very stable and strong and the enlarger balances everything great. The hardest part (except from mounting the head on the column) was to build the trolly and keep everything leveled. In the front I put a door and inside there is storage space for easel, dodge/burn tools, paper, cutter and etc.
I had to construct the trolly this size because of the height and width of the door I need to move the enlarger thru before/after use.
After using the enlarger for a while to figure out what I like and don't like and wich sizes I can print with this setup I will improve it. I will either construct a height adjustable baseboard or buy a table wich I can roll the trolly under so the table will work as a baseboard.
So far I have printed up to 24x30cm with the enlarger and it works great. The enlarger is a beast, but it operates super smooth and easy.