For the 'wedge', it's just a half-moon shaped piece of bar stock. A piece of key stock from Home Depot, and half an hour's work with a hacksaw and files will put you back in business.
For a tool post, take a look at the Enco catalog, or their website, although the one you've referenced will do you well, and is priced well, too.
Enco's carbide cutters and inserts are pretty reasonable, both price and quality wise.