Well I was buying mine before either the 6.3 or the 1.7 diesel exsisted. The boats I considered were; the BWM 21, a Delta Dash, a Picton Cobra, a Ribtec and a Tornado. I visited both the Tornado and Humber factories.
You can get a 1.7 Mercruiser for no more, and less than many, new outboards. I did have the current prices but I've lost track of them. However, do a search here because they were discussed re a twin installation earlier in the year and the costs were posted.