Friend
Any IOS on the 12.3 mainline with the IP plus and 3DES feature will support both Crypto and H323.
For eg. c2600-ik9o3s3-mz.123-23.bin
Check the feature navigator for the features supported by a particular IOS
http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp
HTH
Narayan