I think you want to look at this script here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=5595.18

Just make a single piece, then the script will array ( and perform the randomizations).

As it is, it doesnt do exactly like you want, but in the thread, Michael discusses modifying it to do exactly what you want. You just have to realize the math to put in the 3 functions.