CD write-once disks are an inexpensive backup option and an easy way to take your files with you to another computer. There is no need for a DVD drive at this point. Most, but not all systems are configured with audio. This is a fairly inexpensive add-on. Be sure to specify powered speakers.
Some cheap speakers run only on batteries.
Plus, powered speakers are shielded magnetically so they don't affect the rest of the computer. 16-bit wave sound with powered speakers. Most new computers come with an operating system, but make sure. Windows 98 is highly recommended. The campus computing centers provide great support and are geared more towards Win98 than anything else.