Your budget is suited for a Maramu or Sharki. Both are great boats. I used to own one of the first Maramu's made, hull #29. In some respects, I like the idea of the old Maramu with conventional rig for high latitude work. There's less to go wrong (no thruster, no C-Drive, minimal electrical requirements, no in-mast furling motors, etc. etc.) Even if you can do your own work, a 150K SM is a major project boat, most likely a salvaged boat. If you can find a Mango, that's a good way to go as well, particularly the older ones as I mentioned previously that are simpler.
The people I know who have sailed extensively in polar regions tend to favor very simple boats. I personally have no experience in the high latitudes although I have been stuck sailing with ice on the decks, which I have vowed not to repeat. Ice is best confined to a cocktail glass.