While the OP describes wanting faster acceleration, I suspect he simply wants a lower cadence at his cruising speed, which a smaller rear sprocket will give him.

Few of us with multi speed bikes ride low gears at flat ground cruising speeds so the OP's request and proposed solution aren't unreasonable. (I'm assuming a chainring in the 46-52t range). Rear sprockets or single freewheels are usually less costly than chainrings, so that's the way I'd go.

As to chain length, the OP may not need to shorten or replace if he has horizontal dropouts.

Since the the chain wraps only half way around a sprocket, removing 2 teeth would call for a chain shorter by 1/2" (one link, or one half link depending on how you count).

That 1/2" would be split between the upper and lower loops, so the rear wheel would move back 1/4" to compensate. Therefore if the OP has horizontal dropouts with 1/4" to spare behind the wheel's current position, he's good to go with the same length chain.

Otherwise he has options, cut the new chain 1" (one pair of links) shorter, and move the wheel forward 1/4", or buy a chain with a 1/2" link allowing the chain to be cut to an odd number of links so the wheel can stay in roughly the same place.