as far as i know only code 3 offers a s/c pulley upgrade. tvt machines oem pulleys for a combination of bigger crank pulley and s/c pulley but i dont believe they sell them separate.
as for reliability a few issues in the original production but havent heard of a failure to date. i have a c3 to be installed this weekend after dyno tests. there are definate increases in performance.
the debate has raged whether the c3 was equal to a 178 crank pulley, and the consensus seems to be that they are close to equal. as for a larger crank pulley ie: 181 185 192 these will all outperform but are more costly and tunes are highly reccommended