> Does anyone know what breed
> crosses well with highland.Any
My guess is that you would want to add a Continental breed (i.e. Simmental, Limousin, Gelbvieh, ...) that will increase muscling, reduce fat, and thus improve carcass yield.
Though my experience with Highlands is limited the ones I have been exposed to have been smaller framed, so I would encourage you to use a bull with good calving ease EPDs. Tarentaise and Salers are known for being a couple of the easier calving Continental breeds. You also may want to consider using a Continental/Angus hybrid bull like a Balancer or SimAngus.