bryonhowley has advised you correctly.
I have used a SB Audigy 2zs with Win7x64 for 2 to 3 years now.
I am about to retire it.
The SBAX_PCDRV_LB_2_18_0017 driver package, the first one listed on the page bryon refered you to, is for both x86 and x64 flavors.
The only problem I found with running that card on Win7 is that Win7 does not support game ports.
The game port outlet will not work and shows in Device Manager as having a problem.
I could not run my old MS Sidewinder Pro Joystick on Windows 7 because of that.