You could get piers online at Mobile Home Parts Store at the following link. http://mobilehomepartsstore.com/Merchan ... y_Code=PAP
But you would have to pay shipping. On a quick search, I found these two mobile home parts stores in Illinois. Don't know if they are close, but if you do a search you may find one in driving distance.
Five Star Mobile Home Supply
2100 E Clear Lake Avenue
Springfield, IL 62703
Wildwood Mobile Home Supplies
6755 Giant City Rd
Carbondale, IL 62902
I don't know anything about these stores. Just found them with google.