The belly skid I would go with the thick aluminum. But for the swingarm skid I would go with a Stainless Steel one. Aluminum ones just dont seem to hold up on the swingarm for me. Plus the steel one doesn't have to be as thick and can be easily welded back together.
Heres a link to SS skidplates
http://www.protectfabrications.com/honda.htm
07' Raptor 700 SE- HMF Full System, Pro-Design Intake, HMF Optimizer, Stage 2 Hotcam, +3 TB, Dynatec Programmable w/dl700 custom curves, NGK Iridium, 15/38 gearing, speed sensor mod, GYTR Front Bumper, PRM Grab Bar, Pro Armor Nerfs, Pro Armor Chassis Skid, DG SS Rear Skid, Acerbis Handguards, Tusk P-Brake Block-Off, Renthal/DID, RazrII's, CST Ambush, HiPer CF1A's