Hi Jim,
It looks like that 2900 series switch only has two fiber ports on it. I couldn't find anything in the 2900 series with four.
I would suggest contacting your Cisco Systems Engineer to assist in determining your requirements. You can get product information online at:
http://www.cisco.com/public/ordering_info.shtml
or by calling 1-800-553-NETS.
Does anyone in this forum have any suggestions for Jim based on your experience and his needs?