Don't go for less than 90 in strength and blocking or less than 74 in agility. What you add on top of that is your choice:
- strength if you expect the DE to be strong and you worry to get reverse pancaked or pushed out of the way
- blocking if you want to prevent the DE to shed your blocks early and move on
- agility if you expect your OT to get his blocks shed early and the DE to move around you
Buildwise, there's little room to be creative. Since strength has no good training option besides blocking, you'd need to work on strength first while training blocking + agility. Since blocking has no good second training option, but agility does, blocking is the thing to take care of after strength is done...