I've searched google and yahoo for places that sell chocolate biscuits with no luck. Has any one heard of any place that sells them or can tell me the best place to look.  

Try Cost Plus.

They carry the British McVities brand biscuits and some are chocolate covered. They also carry some of the Aussie Arnott  brand "bickies" though not the Tim Tams unfortunately. DO NOT buy the Mint Slices! They're like cookie crack.

Thank you, I never thought about Amazon.

Maybe try looking on Expo; there is a guy there looking also and he has recieved some good tips, too.

That would be me on Expo. Going to try a couple places in Boston next time I do a transfer there and going to try Amazon.