What dimension are the shelves? That is one thing that is always missing.... a good flat surface to hold stuff!.
I started off with a Manfrotto kit which came with a small shelf, ball joint head, and superclamp (see link). Since then I have had several shelves made by sheet metal shops to fit a MBPro and other stuff. 1/8" aluminum makes for a stiff structure, especially so if you have them roll each edge about 1/2" with a box brake. Add a female baby plate and bodabing, a nice shelf to your own dimension. The cost for the sheared and formed aluminum in the laptop size range is about $35 and I have been using Avenger baby plates like this:
http://www.bhphotovideo.com/c/product/570226-REG/Avenger_F301_F301_Baby_Wall_Plate.html
Manfrotto offers this kit which is a decent value, but the shelf is pretty small:
http://www.bhphotovideo.com/c/product/555507-REG/Manfrotto_311K_311K_Video_Monitor_Holder.html
If you use zinc-chromate primer and flat black laquer, it looks great. If you want a more exotic finish, have it power coated = $$. On the shelf surface, I add HD velcro to secure my MBPro, wireless, mixer, etc.
Grant