Wouldn't bother with that unit.. I did the same thing.. scoured the internet for the parts shown (no links to products given) and was a bit of a waste.
There's much better options out there..
Instead I built a DIY unit with 2 circuit boards wired in series that had 9 channels on each. I used 12v RGB strips, but not "pixel mapping" ones, all pixels do the same colour.
Here's the boards I used - http://www.ebay.ca/itm/30CHANNEL-27CH-E ... SwA4dWMdRZ
If you want to do artnet for pixel mapping though - the parts on the tutorial from garagecube won't cut it.
I'd recommend something like this box - http://www.ebay.ca/itm/DMX-512-Art-Net- ... Sw14xWLLOt
for ws2811, ws2812b, ws2801 strips