Hum I think I've read that the spiderchip has problems with 1.6 xbox. Anwyay, I just bought a duox2 for my uncle and it works good enough for his needs. It comes flashed with the xecutor2 bios (nice blue xbox logo that comes up!) AND evox m8 bios. However, you must use the xecutor2 bios with an 1.6 xbox, it's the default bios anyway. There's a switch on the chip to switch bios. Every game I tried worked fine, installed dashboard and everything, a very good choice.
As for the xenium ice, it's not much more expensive than the duox2, well, at least here. Uploading bioses is so easy with it, you start the webserver on the xenium os, upload the bios with your computer on the network, and voilą. That's what I have, and I love it, but I could have lived with a duox2, there just wasn't any available here when I got my xenium ice (40$ CAN difference in price btw).
edit: even tho silent ace says only the m8 bios will work, it ain't true. The xecutor2 bios that is flashed on the duox2 works on 1.6 and the m8 version on the duox2 doesn't work with 1.6. However, there's a special version of evox m8 available that works yeah, but it's not flashed on that chip, but who cares when you have the other one anyway.
Testing underwear in outer space