a client computer, I unplugged the power to the hard disk and disabled the drive in the bios to emulate a diskless machine
compatible network cards
connection between computers, I used twisted pair ethernet with RJ45 terminators
For two computers a cross-over cable is sufficient, and saves another power point, the first computer shop I went to gave me blank stares, idiots !
For two or more clients, you need a hub, a kit with a 10 mb 4 port hub ,2 cards sells for under A$150, you can probably do better, I've had some success with $5 second hand cards, 3m cables for $6, a new hub for $40, a found monitor and a $60 pentium 75