If you have the fermenters, brew a batch of stout and a batch of bitter or IPA separately then combine them at bottling time. Someone I know does this and the results are impressive.
Split a can of Coopers Stout and put half each into batches of Coopers Draught and Tooheys Draught. Didn't add any additional sugars or malts. Both beers relatively similiar with a great stouty taste. As a Tooheys Old drinker when at the local, I prefer my results.