Should be okay.
Tell me more. Redguard is such a good game. Not being able to play it is a very serious problem. 😀
Not sure what happens to OpenGL support when you have two cards. You might need to install the GF3 dirvers after the Voodoo drivers. Or you might be better not to install Voodoo drivers at all. To be honest I don't know how OpenGL works in this situation. You would be wise to find another OpenGL game and test it.
Setting up Audio on Redguard can be difficult. In the Redguard folder there is a subfolder called sound; in there, there's a files called setsound. Run that and disable sound for now. Also make sure you use Glidos in windowed mode while trying to get new games to work.