I usually run the MSR ultra heavy duty tubes. I would not try and save money on inner tubes. Unless of course you enjoy changing tires in the field or have time to kill in a race, cause your that fast!
The toughest and thickest inner tube I have ever seen and used are the Fly racing heavy duty tubes.
They do make mounting the tire tough, as they are crazy thick and not very pliable when new. They also do weigh a bit more than your typical ultra heavy duty tube. Price may be also slightly more. But if they put tread on them you probably wouldn't even need a tire.
