It looks like Phil J. Rezac's website is down temporarily. There was a notation on his home page saying he was having issues with his web host. Try the link again or Google his name. He also sells his guns on Gunbroker and on GunsAmerica but I don't see any of his ads posted today.
The importer is EAA; you can access GunGenie from its website and perhaps find a local dealer. Here is EAA's website:
http://www.eaacorp.com/
These guns were imported at one time as the Remington Spartan, later as the EAA Bounty Hunter II. Now they are just sold under Baikal if you want to search GunBroker or whatever. MSRP is in the low $300s so you might be able to get one at about $300-ish. They were not imported for a while and just recently became available again and may be a little hard to find.
Personally I'd take this over a Stoeger any day. It's less expensive than a Stoeger to boot.
I have a CZ rifle that I like and agree that the CZ hammer coach is a nice looking gun but they are really stiff out of the box. Now most all shotguns need some tweaking to get them to "run" right for CAS but the CZs are tighter out of the box than the TNN 1878. I've not handled the hammered Baikal to compare it. The CZ is considerably more expensive than the other two.
For CAS the drawback of the CZ is the locking tab (whatever it's called) that protudes between the chambers. The Baikals, Stoegers, TNN and others have a flat breech face and are much easier to load quickly.
The most coveted hammerless doubles in CAS are the SKB and the Browning BSS. These are single trigger guns. Both are discontinued so you are talking big bucks ($1500 perhaps) to find one and get it set up.
There is a cowboy on the SASS Wire who bought a Yildiz single trigger double from Academy Sports and is sending it to one of the cowboy gunsmiths (Goatneck Clem) to have it cut down and slicked up. The Yildiz is a Turkish shotgun (as is the CZ which is made by Huglu) with pretty nice finish and it's a single trigger design. Academy sells them for less than $500 so this might end up being a good midpriced choice.
The Baikals and TNNs are double trigger models. Those are mechanically simpler and therefore less expensive than a single trigger design. A double trigger gun can be fired quickly with a little practice.
I am no expert, just been shooting CAS for a little over a year. Feel free to send me a PM if you want more info.