Hi xdarko,
I have just started building an I3 Box Frame, my 1st 3D printer. I am using boards of Red Oak 110 wide x 18mm thick that I bought at the hardware store.
I think this is much easier as you only have to cut 6 or 7 boards to length and screw them together.
I haven't got any further than that yet as I am still waiting for other parts to arrive.