Donovan Shocks

Bought an 07 w/ 70,000. has 105,000 now. Has Donahoe coilovers (Icon) in front and stock Bilstiens in rear. I don't know how many miles are on fronts but I'm sure rears are originals. Guessing w/ out removing rears ther're shot. Up front one has been leaking for awhile. I'm sure they need rebuilt. As far as replacing rears I'm seeing barely used stock Bilstiens for 50 from new trucks. Does anyone know if they are the same or improved? Is it worth getting fronts rebuilt? Any suggestions would be welcomed. Also I've noticed sometimes when I take off from dead stop the truck feel a mild washboard affect. Only momentary, about 5%of the time.