Ceballos is correct, it is Epic Racing's quad ridden by Travis and a few others. The a-arms were built by Epic and shocks are by Bilstein. I know Epic has a website, but can't recall it of the top of my head. There is no info regarding that quad though on the website, it seems to be top secret! haha. I was on another forum and someone asked Travis why the front tires/wheels on the rear and he wouldn't answer the question. Best bet would be get the number from Ceballos and give them a call for info.
Here is my reasoning for using front tires on the rear, wheel offset. Stock rear offset is 5:2 but you can get front wheels in a 4:1 offset. So if you put the front wheel on the rear you can build a-arms that are 1" longer and keep the same overall width. Longer a-arms, better geometry/more travel. Of course, front wheels are only 5" wide, hence the reason for using the front tires on the rear. Don't know if that is the real reason, but it makes sence to me, so I am going with it! Ozlinc also posted a few advantages.
My only concern with using front tires on the rear is forward bite, since front tires aren't really designed as drive tires. Seems like if you have any motor work, you would get a lot of wheel spin. Looks like it works good though on that quad, Travis and the guys are always near the front of the pack.
Doug