I'm guilty of not fishing the Early black stone nymphs. If I were to use them, I think if you can find a Kaufmanns small enough, you will do well. Montana patterns will work too.
A few things to look for in your purchases are wing casings and antennae (although the Montana has neither but still a great pattern, I use them as a stimulator type of nymph pattern (Great fly's!!)).
Just curious, where will you be fishing these? If it's stocked NJ streams, just use any ole' black or brown nymph in a size 14. I think you'll do well. I would even recommend something with little rubber legs on it. You will start to see many of these patterns around if you haven't already.
I've received about 20 dozen sample flies so far. I'm slowly leaning toward 1 vendor. Slightly more $$$, but supply's the best quality I've seen, so the extra money will be well spent. I'm really going over all of the flies received with a fine tooth comb. 1 vendor sent me 10 dozen sample flies today. Unfortunately, his samples aren't good enough. I'm going to have to tell him no.
I'm still waiting for samples from about 6-7 other vendors. Once I receive them, I'll make a decision and order a few hundred dozen. If anyone has a favorite pattern, you can send it to me with the recipe and I'll see what I can do.
Dennis