Cooler intake manifold

I was thinking about using exhaust heat crossover block off plate's and a lifter valley baffle, insulate the bottom of the intake manifold. The car will not be driven in the winter time. I've read that a cooler a/f mixture is good for power, is this true? Also would a carb spacer be beneficial, if so, how tall and what would be the best material for it to be made from? Best place to locate the air pick up for a cold air kit, and is there a kit available to insulate the duct work for the cold air kit? Are K&N air filters the best for a filter. I have to find ways to improve performance without breaking the bank account.