I have a B16a2 sourced out of a USDM 99 Civic Si. I wish it had more bottom end torque however its a fun engine to play with.
If your going to be doing alot of Daily Driving, Going with the b18c would be a better choice. If you have a long commute on the freeway, The short geared b16 transmission wont be the best idea, 70mph is 4000 rpm.
The Stock b18c gsr Transmission will be Taller Geared and Will have less Rpm's at 70. It will have MUCH more torque on the bottom end. I didn't think there would be as much of a difference as there is.
My B16 Hatch gets 20-22mpg in town, upto 25mpg on freeway.
If I was going to choose between a B16a2 and b18c1 today, I would get the b18c1. The extra torque is worth the extra money.
