re: been thinking along those lines for a while
A good chair is essential, and worth some extra bucks. I build and maintain my own computers, but am not an expert by any means.
Good news if you're a self-employed contractor: money spent on stuff like this is deductible, as is the portion of the house you use for an office. It isn't deductible if you use it for anything else--you can't deduct your bedroom if you sit on your bed and use a laptop.
I work out of a converted garage. As is, I only deduct the square footage occupied by my work space. You can't be too careful with the IRS.