Yeah i agree the blitz and hks fmics are awesome build quality but you can get a decent fmic for a third of the price that will do the same job.
Well the WEPR fmic kit is pure quality, the piping is awesome and the core is a decent size and wont require much cutting of you bumper if any tbh.
I had it fitted to mine with a TOMS bumper and it only needed minimal trimming.
Abit on the piss as the bumper is not on properly but you get the idea.
The jperformance/hdi fmic kit with the massive core is what i have now, it needed a little more trimming of my TOMS bumper, as the core is alot bigger, but is one of the better cheaper kits out there at the minute.
Now my mate has the same kit fitted to his mark 3 gt, and he managed to fit the kit without touching the bumper, all he did was fit the core as far back as possible.
You can just see it there.