I'm up in Z6 but you already have about the best late great keeper in Goldrush as far as I'm concerned. Just as good in a different taste is Pink Lady, but it's bound to be harder to grow than Goldrush. In heirlooms Winesap and Arkansas Black fill the bill. Up here so does Newtown Pippin but down there it might ripen too early to really store well deep into winter. Your season might be almost long enough to properly ripen Granny Smith which they don't seem to be able to do in E. Washington state.