I'd be very leary of cheap cases that include power supply's. cheap power supplys are generally not a good idea, they can fail in 2 weeks, or 2 months, can't tell when, but they will, and sometimes, they'll wipe out a motherboard or hard drive when they go. you will want all ethernet cable connecting them, no wireless.. ither way is just as easy in Ubuntu, but with the wireless you would need to install the restricted broadcomm drivers, but fast wireless is only 100 MBPS. you can run full gigabit with ethernet.. also, if your connecting them togther directly ( no switch ) you will need a crossover patch cable, rather than a regular cat 5/ cat 6 patch cable. if your running 3 computers you will need a gigabit ethernet switch.