I just ordered a C3100 from Dynamism.com. They list the price at $899, but I got them to come down to $729 + $10 shipping. I should have it by Friday.
Dynamism is more expensive than pricejapan, conics, etc. but if you can bargain them down, the reduced ship time and better warranty responsiveness is worth it for US customers (they are based on Chicago and ship from Chicago, not Japan).
Anyways, I plan on doing the "dual boot" thing with the base Rom and OpenBSD. offroadgeek was kind enough to give us an OpenBSD forum, and it's been quite active with folks who are loving OpenBSD on their zaurus! There are kinks to work out but it seems pretty useful and is apparently easy to dual boot.
I love Cacko and will probably try that out as a replacement for the stock rom when it's released. Never tried pdaXrom.
Oh, I just wanted to add that OpenBSD has a million networking tools (many network security related) available. Also, the zaurus port is an official project, and thus has the backing of the OpenBSD project, so it's likely to be supported until the main developers become disenchanted of the zaurus platform (like that would ever happen).