I would suggest at least 2awg for that amp if you're going to run it hard.
I understand the costs of the kits can be prohibitive but in case you didn't know you can buy your wiring and related accessories from the 'Net (and there are multiple trustworthy sources) and save heaps of $$$ over getting an all-in-one wiring kit from like Best Buy or Circuit City or wherever //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif
http://www.darvex.com is a great source for distros, RCAs, power cable, speaker wire, etc. The owner of that site also sells on eBay under the username bag-boy. Close to 30K feedback and is still at 100% positive //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif