Hi,
Any ATX pc chassis without USB ports(in shield)will fit the 164LX MB.
You really do not need the ATX shield, unless you are really worried
about EMI/RFI radiation. The chasis i picked up on Ebay was put together
by:
Axxion Group corp.
1-915-877-5288 
P/N DL 17
Supported video cards for Xnetbsd server are as listed :
http://news.gw.com/netbsd.ports.alpha/11233
supported video cards for XFree86 running on alpha 164LX are:(PCI cards)
1)all Matrox cards
2)most Nvidia cards includes the Riva TNT2 ->GEForce2 MX4/420-> GeForce4
MX420
3)all glint- pm2, pm3 cards -return to text-a work in progress.
4) Savage3D
5)tdfx, driver for the gfx-voodoo3/4/5 cards
6)Ati Rage 128, radeon cards, through the 7000V/E
7)S3virge cards
Best -Mel