Nobody really knows about GF4 compatibility yet other than a GF4 *should* work in any motherboard made in the last couple years.
The current chipset of choice for Athlons is the Via KT266A...and you have a lot of motherboards to choose from. Decide what features you need to narrow down your board selections and then choose a board from that group. Also if you want the Alpha PAL8045 heatsink then that will limit your choices some more as only some of the motherboards out there can fit such a large heatsink.
I personally own the Epox 8kha+ which has been a very popular all around, not much integrated, 6 PCI slot board. The pinnacle of integration would be the Soyo Dragon Plus board which has onboard RAID, LAN, hardware sound, and smartcard reader followed closely by the Abit KR7A-RAID. The MSI board is also the only board that I know of with integrated USB2 if that's your thing.
Most all of the KT266A boards will perform within 5% of each other in all situations. If you will actually use 4 DIMMs then you limit yourself to (I think) just the Shuttle AK31/35GTR, and the Abit KR7A/RAID.
I've had a great experience with the Epox 8kha+ so far and it's one of the cheaper boards out there.
Gaidin