just rotor upgrades for the rear. since you have 20s, you can opt for the stoptech or rotora kits.
http://www.stoptech.com/company_info/news/armada-titan.shtml
http://hopupracing.com/rofr8pibigbr.html
http://www.stoptech.com/company_info/news/armada-titan.shtml
http://hopupracing.com/rofr8pibigbr.html