If I rememebr correctly at a minmum youll need a 14MM socket (front cross member and bolt that connects the front of the diff to the cross member), two 12mm wrenches (drive shaft bolts front and nut side, and axle nuts/bolts) these maybe 14mm but I believe they are 12mm. The nuts on the rear of the diff that holds them into the mustache bar is a 21 or 22mm socket if I remember correctly. Now I dont know what type of axles are on the diff your getting but just make sure you have the usual 10-22MM sockets and a couple of 12,14mm wrenches and maybe a 17mm wrench, a screw driver and youll be fine. All of this is meant for a S30 so S130 or above Im not sure.
Terry