Word. The oem gearset is pretty nicely matched as is, so why change it?
That said Quaife markets B-Series compatible 6spd sequentials with LSD and your choice of 5th 6th & Final Drive Ratio... for nearly $11K!
If you're dying to have 6 speeds, take a K20 motor along with the trans, and have fun.
Plan on custom axles, and a lot of headaches.
__________________
:: :ToDspin: - supermod
- but who gives a shit?
:: HAN Integra FAQ: If, by some miracle, yours hasn't been stolen... check it out!