Yes the Voodoo 4 is supported, but I have heard the Voodoo 3 got better drivers (im not sure, search about it on other forums like amiga.org) I use a voodoo 3 on my A1200 Mediator....
I wouldnt wait for the DVD decoder driver, since it hace been promised for many years now (and never delivered)!
I think the pci is a good solution for gfx/sound/network.. Its abit expensive, but much better than buying a zorro expansion for the 1200.