Hi Silvio,
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps4324/product_data_sheet0900aecd801792b1.html
here you will find the info you need. By the way, be aware that you will be chosing the IOS in regard to what your supervisor is. You can't just pick up one IOS lilke for branch routers or access switches because your supervisor requires atention to its hardware configuration.
Let me know if this link is fine for you and if you need more help post the supervisor that is working on your 4506-E.
Take a look to this link too:
http://www.cisco.com/cisco/software/navigator.html?mdfid=277241601&i=rm
this is the way to find the features you need.
Take Care
Alessio