i got my r33 done at mercury and couldnt be happier.
i've got a 2530 with a gtr front mount, 550 cc injectors, z32 afm, gtr fuel pump, pfc with boost controller. they installed the injectors, z32 and fuel pump and tuned the pfc. i asked for a fairly conservative tune with as little knock as possible to keep it reliable and they pulled 210 rwkw at 1 bar, (just whilst i learn to drive with that much power).
it would be possible with 1.4 bar to get around 240-250 but then you get into issues with reliabilty. get it retuned in a couple of months.
but i found them to be very helpful and very smart when it came to skylines. and all up it only cost me around $900 to fit the injectors, fuel pump, power fc and boost controller and z32 and also alot of time on the dyno for tuning.
thanks
matty