Charity event

Hello guys and gals. I was just wondering if anyone knew who I would contact to see about getting some items signed by players for a charity event I am helping with. My 2 year old nephew has had 95% of a brain tumor removed and is currently undergoing chemotherapy for the remainder. We are doing a dinner dance evening with an auction as well to raise money for Great Ormond Street and also the Brain Tumor Charity. A lot of football supporters will be there many palace so was hoping to get a hold of some stuff for the auction. I have documentation with charity numbers on them for proof that this is legitimate. Regards, Ryan