HI Bro
Yes, the Cisco ASA 5525-X can surely perform based on your requirements. The 5525-X IPS Edition has built in content filtering, but you will need a yearly subscription to Cisco Scansafe which is their "Web Cloud security".
As for bandwidth limiting, the method is still the same via MFP i.e. class-maps | policy-maps
Lastly, you might want to enable Cisco NetFlow. This will give you a better monitoring on users, utilizations etc.
http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_tech_note09186a008084de0c.shtml
Warm regards,
Ramraj Sivagnanam Sivajanam