My preemptive apologies for resurrecting a 2-year-old thread...
Just in case you haven't checked in the For Sale or Trade subforum lately, I pushed the button on a new effort to get more P112 kits made. This time I'm using Kickstarter.com to handle the messy work of gathering funds and there's more peace-of-mind that I won't take the money and run (like I'd do that and live). Anyhow, see
http://661.org/p112 for the details, a link to the Kickstarter project page, updated manual, and so on. Costs have gone up and I really didn't want to go through sorting thousands of tiny parts again. So, the kit this time will include the board, surface-mounts mounted for you, two CDs full of stuff, and two serial port pigtails. The price is $100 in the US and $112 outside the US. At the P112 website there is a parts list with links to the parts webpages at Mouser, Digikey, and Jameco. Most of the parts can be bought from Mouser. There's a link to a Mouser Project where you can instantly order what you need (or delete stuff you already have). Mouser doesn't have the RS232 chips, so go to Digikey for that. Jameco has connectors and crimpers.
Terry will be assisting me again with burning roms and I'm sure he can be cajoled into building your P112 for you.
Please go and put down your pledge. Funding closes on November 12, so please go there and tell your CP/M-using buddies to do the same.
Now, about cases, an old SCSI chassis that takes a full-height drive will make a nice P112 chassis. There's usually some place inside where you can mount the board. See the webpage for pictures of mine. If you need to make a mounting bracket, it's pretty easy to do with aluminum plate, L-extrusion, and standoffs. A dremel and file are all I used to make my bracket. If you need to drill steel, go buy a nitride-tipped bit so you won't ruin bits like I did.