Custom ground reamers are available from
http://www.pacifictoolandgauge.com,
http://www.mansonreamers.com/, Clymer, Forgreens and others.
Pacific Tool has a printable reamer diagram that you can fill out with the dimensions you want and send it in. The person there to talk to is Dave Kiff, I have heard that he is the go-to guy for custom reamers. I have used PTG reamers but have not spoken to him directly.
You can have custom dies made by
http://www.ch4d.com/ and I believe RCBS and LEE will also make custom dies for you if you send a print and/or cases.
I have made my own reamers and form dies and reloading dies, it's a bunch of work but it's fun to make a one-of-a-kind.
You need to know what case you will start with and what you want it to end up as. You can chamber a rifle without formed cases and then fire form cases to fit. It's hard to describe the process.
The other trick is to get load data for a wildcat, you have to find something with similar case capacity FOR THE SAME BORE SIZE and reduce that and work up CAREFULLY. Good reference for that is PO Ackleys books "Handbook for Shooters and Reloaders Vol 1 and 2". One of them has an article on how to make reloading dies also.
Wildcats are also addictive, you can't have just one so watch out.