Magna doodles / magnetic drawing boards - what's the largest one I can get ?

[HappyJoyful]

ideally need to buy this today so any tips on where to get it appreciated.. my quick search indicates I think Tomy's is the 'orginal' and get's best reviews and seems to do the biggest... But, obviously there are others? anything bigger? I know my CM has one that seems v.big but possibly an older version of one. Suggestions appreciated asap, terrible me for leaving till last minute