RAID 10 data recovery tool recommendations

We've recently had a disc in our 4 disc RAID 10 array fail. The faulty disc has been replaced with the bios menu now showing: 2 x discs OK, 1x disc Replaced and 1 x disc Degraded. During the rebuild process it reached 70% then failed. The machine is now booting from a piggy backed IDE drive and the IBM RaidMan interface says it is rebuilding but gives no time-to-finish or progress indication. It has been running for 24hrs+ without completion which I'm guessing means it never will.
What data recovery tools do people use when trying to recover RAID 10 arrays? There seems to be plenty for RAID 0, 1 or 5 but few for RAID 10.