There aren't many choices for releaseables. I had this setup-Voile 3 pin cable bindings on the Voile release kit. This is not the same as the CRB which is sold as a unit. The whole setup costs about $165 US retail ($85+$80 for the release kit).
You've probably looked here already, but here's their site-www.voile-usa.comhttp://www.voile-usa.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=VEOS&Category_Code=VTB
I only had one of mine release once when I fell backwards going uphill, but I only used them a few times, so that isn't a good marker of how they will work, but it did work.
I bought a used pair of hardwire CRBs online, but after looking at them in person, decided to get the cable bindings and kit instead. CRBs are more of a telemark binding, than a bc binding. With mine, I never even used the cables, just the toe pieces. If I was doing some downhilling, I would have added the cables, but never got around to doing that. One thing about the CRBs is that if you always have the wires on, you can use the CRB without the 3 pin which is much easier to get in and out of, but I have a feeling they won't be as easy to ski on for travelling on the flats or rolling hills. Just an assumption.
There are some releaseable tele bindings, but they are heavy and expensive and the boots are too.
You may want to ask on www.telemarktips.com
. That's where I got some good info before buying my setup. One thread there has a whole dsicussion on bindings and a couple of people said don't use CRBs with leather boots.http://www.telemarktalk.com/phpBB/viewtopic.php?t=74467&highlight=releaseable