Regardless of whether you select a 32-bit guest OS or a 64-bit guest OS, if the physical CPU is a 64-bit CPU, then the virtual CPU will be a 64-bit CPU. (For a 32-bit virtual CPU, you have to specify the additional configuration option, monitor_control.disable_longmode = TRUE.)
For Windows 7, in particular, I don't see any issues with your configuration at present. Given the age of Windows 7, that is unlikely to change with future releases of vSphere. In general, however, it's best to select the guest OS type that most closely matches the installed guest OS.