If you must have a Lehner I found one
here. Personally I'd rather have a Neu or MedUsa. You get more poles and a slotted stator, meaning a lot more torque.
If you do go for the Lehner, make sure to get a RC-M Bore Reducer, they use a 4mm shaft on that motor rather than the 5mm shaft you get on a MedUsa or a Neu.