Bantams are ornamental breeding Macgro7, so there will probably be no bantam counterpart for a dual purpose breed. Given that they are defined as a quarter of the weight of their large fowl version and yet have the same number of feathers, using any for meat isn't going to be practical. I can however suggest Leghorns for eggs- they lay 32 grammes upwards, which are completely disproportionate to their size. We've never had prolapse problems with any of ours, but they can fly extremely well. Any enclosure needs to be over 5 feet without a solid top edge, otherwise they will land on it and then fly down.
Another alternative is TNN's, but the bantams are so cute I certainly couldn't despatch one. They are good eating but go broody when they have laid a clutch of just 6 and stop laying for weeks, so keeping them for eggs is going to be hard work. They do come almost ready plucked though, but as a consequence consume a lot of feed in colder weather.