Just as an example of a nice shuttle
http://cgi.ebay.com/New-Shuttle
I am not saying to buy this one. This is only for comparison. If you open yourself to the possibilities, you may find something that you will be happier with in the long run. I like to use local computer shops. You can spec out a machine and have them help you. The trick is to have them build it like it was a gaming machine. The operating system should be clear of any crapware, free trials, or other advertisements. You want a lean and mean computer to use for your business with only the bare essentials installed. All the other crap just steals system resources from you business. You wouldn't let anyone take one penny from your pay, why should you pay (in computer performance) for someone else to have their ads on your computer.