You shouldnt have any trouble finding the single on Hardleaders, Ive seen it in HMV and places like that so it cant be that rare! But if you cant find it, its also on the Movement Perpetual Motion sampler.
@ M Code - 'That Amen Track' is a remix of F2B, but they couldnt call it the F2B rmx, cos they wanted to put it out on Valve, whereas the original was obviously on Hardleaders. Im pretty sure thats why anyway.