I've used the AN8-Ultra, which is basically the same thing as the AN8-SLI but with only one PCI-E slot. It was a very stable board and I didn't have much trouble getting everything set up. In my mind, the AN8-Ultra and AN8-SLI are both fairly good all-around; they've got a silent northbridge heatpipe, a port 80 diagnostic utility, and a nice assortment of features to boot. The uGuru programs, although simple, are helpful. And despite the fact these ABIT boards haven't been talked about much as of late, they're generally very overclockable but if you want to really push your RAM to the limit you may want to pick up some active RAM cooling since the slots are very close together.
And to answer your second question, yes, it will work with a Guru panel.