It's not really a matter of whether ACS supports this, but whether your non-cisco device does. ACS simply receives TACACS packets from external devices and acts upon them accordingly, so if the non-Cisco device can send TACACS packets to ACS then it should all work fine. You would have to check with your vendor to sdee if they support TACACS.
Keep in mind ACS is also a Radius server and pretty much any vendor will support Radius. If you want to do command authorization/accounting though you have to use TACACS.
You can configure vendor specific attributes here:
http://www.cisco.com/univercd/cc/td/doc/product/access/acs_soft/csacs4nt/acs33/user/ae.htm#wp365540
