I pinned it. I've done a few in the passed. Even pinned some for other members by request.
Reamer, tap, pin can be bought anywhere machining supplies are sold. McMaster is your best friend!
Chain stretch will over shoot the actual vtc advance. Log your vtc via Hondata and you'll see. With 04-05 pistons running 45*+ chain stretch is dangerous! 40* is safer. The 5* of difference would be negligible in gains anyway. Better safe than sorry!