Anyone know where I can buy bunk carpet in bulk, as in on a roll and not pre cut to any standard dimensions?

This grade of carpet, 16 oz, is the same as bunk carpet.

http://www.boatcarpetcentral.com/standard-boat-carpet

Perfect! Thanks.

Home Depot sells commercial grade runners in bulk by the foot. It's about 2ft wide, and designed to go in hallways and other high-traffic areas. Just pull off the amount you want and cut it off the roll.

I cut the runner length-wise (rip cut) and can do two bunks that way. Did it years ago, and it's held up very well. Will do it again once the carpet wears out.