The Maximum chips pre-soldered to an adapter are available from Proto-Advantage ( http://www.proto-advantage.com/store/
I have attached an image from my last invoice when I ordered 3 Max chips. You might need to contact them ( firstname.lastname@example.org
) before placing an order to be sure they are still available and part numbers or pricing are the same.
As Jeff said, soldering them yourself to an adapter or pc board can be extremely difficult without the correct tools, so I believe Proto's price is very attractive.
I have a simpler circuit using the Maxim chip but with fewer parts. I have made a couple of prototypes for myself and Jeff, but I have not finished a pc board layout. Email me if you want a copy of the circuit design so you can try it instead.