Thanks guys. I am looking into buying in some aluminium plate now and saw that Smith Metals was recommended on here. As they are local, think it might be worth checking with them also. They have a few options for aluminium tooling plate on their website: http://www.smithmetal.com/aluminium-tooling-plate.htm
What option would you guys recommend, would it be the the KASTAL or would any of them do the job?