Make your own cable... For a roll over, the colors for both ends are:
WO O WG B WB G WBr Br
HOWEVER, you flip the connector over on one of the ends before crimping. You'll end up with
Br WBr G WB B WG O WO
A crossover uses one end with the above cable layout, but the other side has a different set. I forget right off the top of my head, but basically you switch the in/out cables.