Here's the ordering guide if you are a partner:

Ordering Guide for Cisco Customer Contact Solutions

If you are a customer you need to work with your local Cisco Partner. They will need to place the order for you and can help to properly design, size and guide your deployment. There is a fair amount of sizing that you need to go through to ensure the product will meet your needs. For example, there is no way you'll be able to get 300 concurrent email-enabled agents using CCX. Again, this is what your partner is for.

Also since you seemed to mention the eGain WIM/EIM products: They have reached end of sale.
http://www.cisco.com/en/US/prod/collateral/voicesw/custcosw/ps5693/ps7236/end_of_life_notice_c51-517363_ps7236_Products_End-of-Life_Notice.html