Does the system have a Plug&Play capable BIOS? If not, it's easy. The AWE64 does nothing if not initialized by Plug&Play or CTCM. So in pure DOS with no Plug&Play, you can use the SBPro and the AWE64 is more or less invisible. In Win98, just use resources that are not taken by the SBPro or GUS and all is fine.
And while dr_st has a point here, I'm not sure if it works that way. The SBPro is not a Plug&Play card. It will use the resources it is jumpered to no matter if enabled or disabled in Windows. Windows can not control the resources used by a non-Plug&Play card. So be careful if you plan to use shared resources - it may freeze the system.