Someone managed to skid into my car today while it was parked up.

Obviously i want the car fixed but i`m 95% finished putting in the 24v engine and havan`t told my insurance company yet as its not finished.
How does this affect me if i want to make a claim? I can fix it myself if its paid for, but how much do i ask him for if i don`t use the insurance company? He`s mainly fooked the rear bumper and all the brackets, but havn`t opened the boot yet so will check that in the morning...
Cheers, Ed.