Keep you eye on the local classifieds in Ontario. A couple months ago I saw a couple of complete D950 engines come up for sale on kijiji. You could take the head and what ever else you needed and then part out the rest.
Not sure on the market but I'm sure like anything the harder you work at it the more likely you'll sell the parts you don't need. I'm not sure if you priced out a new head but I think I heard they are around $1200 new and a used one if you could find one are about $600 (plus taxes and shipping?).