1. First thing, you must have to get the details requirement from your company. Depends on your needs, you must have to get the quotation from the different manufacturers or retailers like HCL, Compaq, Dell, and Sony etc to get the prices.
2. Second most important point is you must have to get the different quotation based on your requirements like Celeron and Pentium processor. Depends on your usage you must have to get the quote as per specifications.
3. Third most important point is you must have to select the monitor based on your needs. The majority of the company uses the flat monitor now days so you must have to select the flat monitor as per your need.
4. Fourth criteria for select are the high capacity hard disk. It is available in different capacity right from 30 GB to 60 GB space. You need to install it based on your need. If you are using LAN than you do not need more capacity hard drive.
5. The fifth point is the RAM. The RAM important part to operate your PC. You must have to select the RAM from 64 to 1024 MB.