Items 20 & 26 are "no problem"!
Item 22 has been discontinued by GM for a few years and I see no inventory on dealers shelves anywhere in the country! I wouldn't think the supplier that you mentioned could help you with it either.
If they've supplied you with a quote including part numbers PM me with the information or post it here.
There are likely item 22's out there but NOT on dealers shelves.
There's a good chance that if there were one out there it would "surface" at the Carlisle event this weekend.
#22 right side frame rail part # is 12529346.
Several members frequent the place, maybe a few dozen "pairs" of good eyes can spot you one!!!
The "event":
http://carlisleevents.com/ce/events/corvettes/