Second getting the Yanmar if it is in good condition. A new one will run you easily more than $6,000. Even if you don't install it now, you'll have it for when you get round to it. Make a nice conversation piece in your living room. A 2 hp outboard will get you in and out of the slip and they are available
cheap in the interim. Had a
Columbia 26 and only used the
engine once in a year to get home. Sailed the boat every weekend and usually during the week and many trips to Maui Would sail the boat to the slip and use the
engine only to maneuver into the slip. Had an upwind slip and often sailed into the slip after gaining a little experience. One caution, that was in
Hawaii with very reliable tradewinds so virtually no days without some
wind.
Of course, that gets back to do you need an inboard at all?? If you aren't going anywhere, an outboard, even a small one, will do just fine. If
Mexico or other regular trips to the Channel islands are in your plans, a
diesel inboard would be really nice to have. Outboards don't do well if there is any sea running and can be cantankerous exposed to the elements hanging off the back of the boat.