Competition Clutch

Or you could just buy from a bearing shop
Clutch Release Bearing - NTN-FCR62-32-14/2E

Probably half the cost that Nissan want for them

There are about 3 part number options from nissan for the R
They cross fit D21, Terrano, Almera & Maxima.
Also same bearing as in TD27 london taxi lol ...
The Blueprint one is good & is oem NTN bearing too (normally) .

as mr b says - the london taxi bearing works, i have one in my car:
http://www.ebay.co.uk/itm/ADN13313-Clutch-Release-Bearing-fit-LONDON-TAXI-TX1-2-7D-Taxi-TX1-97-01-RWD-/301226895053?hash=item462285a6cd:g:AjwAAOSwo8hTrBxw

and i have comp clutch stage 4 pressure plate, disk and flywheel. good kit for good money. lots of mitsubishi people use them. But I did find the stage 2/4 pressure plate to be very heavy (they told me the stage 2 & 4 pressure plates are the same for gtir).

being a daily driver I have just bought the stage 1 pressure plate which is lighter, i'm gonna put it on in a few months time. The reality is if i'm daily driving i'm only ever gonna be 300ish bhp.

eurospec use comp clutch equipment in many of their race cars, this is where i bought it all from, good lads at this garage:
http://www.euro-spec2000.co.uk/

i also have comp clutch lightweight flywheel - it weighs 10.5lbs, the standard nissan was 19.8lbs, both measured on my bathroom scales so not 100% accurate but close enough. I cannot recommend this product enough!

lightweight flywheel feels like the performance difference you feel between a car with passengers and full tank of petrol, vs. just you and an empty tank...

if you do the maths it is impressive:
http://www.uucmotorwerks.com/flywheel/how_a_lightweight_flywheel_works.htm

if you get one then note the bolts on gtir are 11mm but the flywheel for sr20det 200sx is 10mm. I just drilled holes out from 10-11mm with hand drill...

It's pros and cons Tho. Think mine was lighter but was not massively impressed with lighten fly. I ran a 2860rs so boost was min lag anyway but I found soon as you back off the car loses momentum faster so it's depending on your preference

Agree with the comment you lose momentum quicker, but with a bit of practice you learn to let go of the throttle slower, and/or you can use the increased engine braking power to foot brake later in to corners. You spool up quicker because you can rev quicker.
Cruising around town it definitely makes driving a bit more animated/revvy/awkward, and it's easier to stall because there's less momentum, but I've learnt to deal with it, and for cheap money if your box is off, the acceleration (and deceleration) increase is great fun. End of the day the gtir is a race car

Within  reason anything lighter is a bonus. Like I say follow the route of what you use the car for as you have.