The supporting equipment and tools for your shop can often be found in the same places that you are looking for a press. The great news is that many of these tools are still being made new today, and many more still are available on the used market.
Other Print Shops
First and foremost, ask local printers for ancillary equipment. If they are selling you a press, ask them about what might go with it as a package price. Furniture cabinets, quoins, and roller gauge’s are all necessary supplies, and one-stop shopping is convenient, if nothing else.
Many printers will buy up equipment when it is available, not necessarily because they need it. A posting on your letterpress classifieds or to your email listserv may connect you with a sympathetic shop to is happy to sell you the piece you need.
PPL (Photopolymer Listserv)
S.F. West Coast Letterpress Printing Listserv
Ladies of Letterpress
Most dealers of used printing equipment keep the basics in stock at all times. Unlike a press, most ancillary equipment is light enough to ship affordably. If a particular shop doesn’t have the particular piece you need listed online, try calling them. If they don’t have it in stock, at least you can let them know you’re looking.