From reading the forum, it sounds like I should be looking for Aloha 32, or Ontarios, and I have heard Tartans mentioned many times. The broker suggested CC as they are solid glass cores.
What are your opinions on Northern Ketchs. I could not find any information about them but I did find one for 40k which I am no finding suspect considering it is a 38foot boat.. seems a bit low.
I agree on the recommendations to pass on this one. I think you will find other Niagaras in this price range. Mine sold for CA$66K and it was in outstanding condition and very well-equipped. I would not avoid these boats because of core in hulls - most have no problems, especially if no holes have been drilled through the cored section (the hull was laid out with solid sections for various through-hulls.)
Overall, I would think that Hinterhoeller build quality is better than either Aloha or Ontario, but the latter boats are decent quality too and if the price is right. The Northern 37 is not well-known (not many were built) and are decent, basic boats. I had a Northern 29 and the build quality was OK, the problem was that it had an early IOR hull form and did not sail all that well. Not sure if this can be said for the 37. Some 37s were sold as hull and deck only and the overall quality will depend on how well the home builder did.
It sounds like you are in Canada from the boats you are talking about. You certainly should look in the US - prices there are very reasonable and there is a very large range of boats to choose from.