Systems are Custom Built to suit your computer use and requirements, call or email for a quote. Below are some examples.

Some information about new computers and components
For entry level and if games aren't a priority: Integrated (part of the motherboard, also called onboard) VGA (video) motherboards are fine nearly all the motherboards have the option of adding a separate video card later if required.
TIP: Stay away from motherboards without an AGP slot, they are rare these days.
Remember for better performance integrated video does use up large amounts of memory. eg An integrated video card set to use 64MB of memory, leaves you with 256MB - 64MB = 192MB of available system memory.

Onboard or integrated sound is fine unless high sound quality is a priority. Integrated sound with a reasonable set of speakers is quite capable of waking all the neighbours.

CD writers commonly called CD burners are now very inexpensive for the advantages they provide. My first CDR/RW cost $600 now they are available for under $90 allowing you to write and backup large amounts of data to inexpensive CD media.
TIP: For an extra $50 go for a CDR/RW in any type of system.

Keep in mind that your keyboard and mouse are your tools to input data and interact with your computer they should be reliable and comfortable.
TIP: A mouse with a scroll wheel will increase your productivity when working on a computer.
TIP: A ball mouse can become blocked with fluff and can easily be returned to it's original performance by removing the plate around the mouse and removing the fluff with tweezers. Optical mice do not have this problem and can be used in most cases without a mouse pad.