The various MythTV distros keep getting better. Just check if they support the card. It all depends on whether it uses a known chipset, or if the manufacturer won't provide any information on it.
If it is supported and you can't find packages for OpenSuse you can always build your own. There's a wall over there to beat you head against.
http://www.mythtv.org/wiki/Leadtek_DTV-2000H