Yup. We had a steyr on our old cougar. Great engines, ideal for ribs lightweight and free revving. Really impressed with ours although not cheap to service. Mitchell's are agents for them but mermaid will also look after them and relieve you of less money or the pleasure!!
I spoke to nick when I was looking for info on ours and he was really helpful. They push the phantom 3 along really well so that has to show something!!
I haven't looked a new prices for a while but I think they are a fair amount more than the same hp Volvo / yanmar and I know the new yanmars are pretty good and lightweight. Cookee will be able to help on them as he has a few!