I am doing something similar, turning my former stage stand, a QuikLok Z-726, into a studio workstation similar to the Z-WS71L with add-on shelves for speakers, computer keyboard, CPU stand, a lower rack mount for a mixer etc. Some dealers have told me that certain components of the Z-series stands are discontinued so I've had to bounce around the web to find the various parts I needed from different shops... some have the parts in stocks still. So I've nearly completed my studio workstation except that I'm waiting on my computer keyboard tray to arrive.
I like the Z-series stands and they built like a tank, but had I not already owned the Z-726 as a starting point I'm not sure that I would have put this much money into a QuikLok workstation. I would have just got a regular computer workstation from Office Depot or something and modified it to suit my needs. I'll probably wind up putting at least $350 into this project. OTOH I don't like pressed wood so maybe the Z-stand is the better choice.
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Jim Eshleman