Good stuff, but probably expensive too.
I would need all the priducts twice and for the harddisks I need 4 , for each PC and probably there won't even fit 4 of those in each PC.

This was the material I used;
1 large shelve of plywood Euro 14,95
(250cm x 50cm x 50cm)
1 pianotype hinge Euro 6,95
Some wood for construction Euro 2,25
Screws (had those)
4 trolleywheels Euro 9,95
(to pull both towers out easily in case needed)

So that's euro/US$ 34,10 totally
The only tools you need is a saw and a screwdriver.