yes, by all means, build it yourself. Use wood, as metal can hold a static charge. High shelf for monitors... I suggest a tool RACK hanging from monitor shelf. Also, get a small parts bin to hang from the bottom of hte shelf. Drawers are nice for things you use sparingly, but try to keep commonly used tools within sight/reach. Perhaps consider a pegboard backing. Pegboard is always useful.
Key a bundle of wires all tied together. For instance: the mouse, keyboard, monitor, modem (if aplicable), network cable (if aplicable), and power cord. keep them on a string hanging from the bottom of hte monitor shelf, but out of the way. This way you are not fishing under the bench to collect those cables back together when you need them.
Get a light. You know, one of those lights that clips to a shelf and can be put in any position (swivel neck/arm or flexi neck.. whatever). This will give you more light on your subject, but will also let you move it out of the way when not needed. Also keep a small flashlight available for those tight places.
There are probably other things... but these are the things I did.