Hi Ray be good to see you again, not done any of the jobs your looking at myself but sure someone has.
Regarding the sill I think you got away with that hole most would have failed it ! As for repairs to it Tom Hobbs is the man , but I believe he's booked till Easter, he did my ZT and it's perfect. He'll spray it too if you supply a rattle can and waxyoil the chassis if you supply that too
His contact details are on his web site http://www.tjhobbs.com/contact.html]