Yes, Xenium is the best bet for a 1.6
Quicksolder method is where you directly solder the Xenium to the xbox motherboard, no wires, no pinheaders, no nothing, you just put the xenium flush against the lpc spot and solder it direct. Its hard to remove though, so is not recommended unless you really know what you're doing

I recommend pinheader installation myself, especially if you're a hobbyiest

To flash M8 to the Xenium you do the flashing from XOS.
The easiest way is simply to ftp the bios you want to flash to your xbox, then flash it via XOS.
You can't use Slayers to do the flashing on a 4th gen mod (like the Xenium)
You can use Slayers 2.6 to setup the hard drive though.
Read Cap's guide to installing the ICE
The 'loom' worked fine on *my* 1.6.... I used the top d0/lframe tho... if you want to use the bottom, you just need to extend the blue wire...
On a 1.6, just use the bottom lframe (its easier) and run a wire from it to the d0 pad on the top of the chip. There is no need for ground unless you use the wire loom. If you just run a wire from the lframe to the pad on the chip you don't need a ground wire.
IT IS why you can't boot the onboard bios because you grounded the lframe which makes it impossible to boot the tsop. Don't use the loom, just disconnect it and run a wire from the bottom lframe to the top d0 pad on the chip.

One is white, the other is blue
"The Xenium Ice is not the Xenium Blue"! Right, there's my problem right there. I assumed the reference to Xenium Blue in cap's manual was because of the proximate discussion of the blue wire loom and we all know what assumptions can do in the hands of the ignorant. Looks like just a bit more soldering to get this to work the way it should. On the other hand, having the MS dash disabled means no XBox Live which means that topic of discussion is closed with my boys and I save a few bucks.
Thanks for all the info, guys.

Cap needs to put a pictorial comparison of the two chips there with big friendly letters pointing out the difference (ie BLUE vs ICE)