Was just writing a reply to your 1.8 thread when you deleted it.
The R/S ratio is of a concern reliability-wise, at high RPM it will eat rings quickly and I believe this is the reason there are more B18C bottom end failures than on the B16s. If the car is only ever going to be used for track work then you are not really going to need that extra low end torque, where you'll be using the powerband most there's only about 10blft between the two engines as stock anyway.
It's the same weigh up I am having at the moment, except where yours is short geared and constant high RPM track use, mine could really benefit from the lower end torque for sprints/autosolos and daily driving. I vote 1600 and get the revs up as much as possible to really make the most of those short gears.