390s and 660s run about the same, 660s being more durable and 390s easier on the operator until they start crapping parts. That being said, stock 390s are pathetic with a 36" bar.
It would be 2188s around here, they are sold with 20" and 24" bars and not many get sold, cause they suck. You would need to "torque" modify the crap out of a 390 to make it competive with a 2094.