Great minds think alike: I also am looking for large-fruiting crabs, specifically:
Kerr
Martha
Norland (debateable whether this is a crab but...)
Trailman
Red Vein
Transcendent
Yellow Siberian
Also any of the amazing russets such as golden russet or pomme grise or Hudson's Golden Gem. Fedco...
Last year I was planting trees up to Christmas here in Zone 6A (a little warmer than you). You can plant trees up to ground freeze I am told - trees take it in stride. Get planting!
You haven't had a frost yet? Are these Goldrush frost-immune? When should they be picked? Great-looking tree and man - wish I had done this 8 years ago!
All these late Autumn-ripeners really require a month in storage before sinking your teeth into them. They really are the true "keeper" apples and get better with some time inside.
Re: Post #148 - I finally tasted CrimsonCrisp last week. Bought a peck and took 'em home. They are also a GoldRush-lite... great apple and growing a tree in the backyard....