The odds even in upstate New York of a 6-8 acre pond staying cold enough with enough dissolved oxygen to support brook trout is highly unlikely. Unless the pond had a MASSIVE inflow of cold spring water and it would have to be MASSIVE... Brook trout need water temps 68 degrees and below with dissolved oxygen levels above 4 ppm.
If the pond did have these conditions, SMB would likely under perform as they'd never see water temperature that they grow best in... In general, you either have a cold water fishery(trout) or a cool water fishery(SMB, WE, HSB) but not both.
The rare time you get both is when you have a "two story" fishery and you don't get that in ponds or even small lakes.
I'd first research construction of the pond and get that set first and then as that settles, research the fish community for it...
