not a direct answer, sorry.. but if it helps, I have the ram air induction kit.. and my induction hard pipe is also 70mm.. i remember measuring when I was buying an end cap to fit inside the silicone pipe (to make a boost leak tester).
I can assure you, the silicone pipe you'll need will not be a straight diameter pipe, the turbo inlet is definitely smaller than the induction kit pipe so yes you will need a silicone reducer pipe. as for the size of inlet, sorry I cant help.