The job market is tough right now. This makes it attractive to stay in school. Rather than getting a MS in Computer Science you should consider getting an MBA and focusing on your communication skills (writing and presentation). I have a BS and an MS in Computer Science but have observed those with a BS in Computer Science and an MBA. I believe increased communication skills and general business knowledge will open more business areas to you and once there will help you to excel.

Depending on how old you want to go with the interfaces, it may be easier to start with an older ISA bus based PC and adapt new technology to it. The older could handle 3 1/2 and 5 1/4 media already built in. Going to card reader style input could be configured to a serial or parallel port. For tape drive interfaces there were a number of special PC boards on the market 20 years ago to interface PC's to reel-to-reel drives. Then you would need to add an interface between the older bus structure and the USB to open up remaining devices.