Refurbishing a 23' Scottie Craft w/ AQ170 gas engine

Hey all! I recently picked up a fixer-upper boat that has been sitting for about five years. The engine, an AQ 170 straight six needs to be replaced as the cylinders are severely pitted (probably would require boring or sleaving to repair). I am looking for suggestions on possible repower options and any suggestions for improvements on the canvas shade that was standard.

In addition I have removed the deck (it was pretty spongy) and have started to replace the floor supports and closed cell foam along with the fuel tank and fuel lines. I look forward / hope to hear any suggestions or comments you have!