H22 or K20 I agree. K20 beats it in terms of power, and I think the torque is close. I've seen that 2.7L that you're talking about in acura's in the junkyard, it's a VERY big motor compared to these 4 bangers.plus you might have a problem with the height, I'm not sure. YOu might end up having to cut out a giant hole in the left side of your hood and making a massive, stupid looking cowl for it. Plus that 2.7L motor/trans is gonna weigh a few hundred pounds more than your stock four, and you'd have to figure out how to put a much stronger suspension in there to accomodate the weight, and even then you'd still probably have one incredibly nose-heavy car for having all that weight in front. And these coupes are already nose heavy due to the lack of weight in the rear. And, adding a few hundred pounds to a featherweight civic, is going to make it so heavy that that 160 hp/tq won't even be fully realized man. Stick with the fours.
Like the one guy said, you could put a chevy 350 in there if you really wanted to, but for the lack of real power with this V6 motor, not to mention I don't see too many aftermarket parts for it, it really wouldn't be a good idea. Hell right off the bat the H22A is stronger, so why do it? Just go H22 or K20 dude. I've got a stock B16 in mine and it get's the job done, plus the sky's the limit as far as bolt ons.