I just purchased the KDP kit from TST.
Although there isn't a gear case cover gasket used on the 24v engines (RTV is used), I purchased the gasket from Cummins NW for a little less than $20. It's not required although, I personally prefer to use a gasket and some Loctite 515 (or 518) on the sealing surfaces of the gasket (it allows for a better, more leak and weep free installation).
I believe the front crank seal is the same on both the 12v and 24v engines (based on installation instructions from TST).
And remember: DO NOT lubricate the Teflon seal wipers... they have to be installed DRY so they can "burn-in" as part of the seal break-in process