There are 3 different models available for Sup-720.
Sup-720, which doesnot support MPLS but supports rest all the available IP routing features.
Sup720-3B, Which supports MPLS and all other IP routing features.
Sup720-3BXL, which supports MPLS with upto 100000 routes entries in hardware.
The following link should help you understanding all the major differences between the different sup720 models.
http://cisco.com/en/US/products/hw/switches/ps708/products_data_sheet09186a0080159856.html
There are a wide-variety of modules supported on Catlyst 6500. Please see the link below for more information on all the modules:
http://cisco.com/en/US/products/hw/switches/ps708/products_data_sheets_list.html
HTH,Please rate if it does.
-amit singh