tbh I don't think you can go wrong with the Ayrtek bag, looks well made, lots of space and looks like it'll be durable. Also with Tom you're going to get top class customer service.
Biggest bag ive seen was my old one - cant remember exact model but it was a totr kook one, probs replaced by the pro 1000in fact it was too big, check the size of your boot before buying a big bag lol
I ordered one of these last night, http://www.duckandrun.co.uk/Cricket-Luggage/2011-Duck-and-Run--Deluxe-Double-Decker-Wheelie-Bag/detailsgets delivered tomorrow.
Give us a agoutis u decide u want one, fair few lads on here have one now as a good 20+ have gone out since the new batch arrived last month!