I sold my 440 injectors some time ago - the nissan 200sx boys are always on the look out for them. I did have a set of 850s, but settled on the 720s as the spray pattern of the 850s was not as good.
My engine was not a bought unit - it was built to an agreed spec by Steve Guirey (SMG) over almost a year and many many telephone conversations with him. Steve is now squeezing around 1,000bhp out of his 2.5 litre and running low 9 second quarter miles! The last time I spoke to him he had just put his car on Surrey Rolling road for mapping and got 850bhp at 1.4bar before he blew the headers off. His car now runs 2bar with a 50bhp nitros shot (which can be upped to 150bhp shot).
My engine is very similar spec to one of his old ones, just with some better bits and is easily capable of sustaining over 550bhp, just needing a bigger turbo and remap to achieve this (oh and stronger gearbox)!