Standard Exedy replacement will be fine: http://www.h-dev.co.uk/product_info.php?cPath=78_169_293_488&products_id=25430
You'll probably need a new flywheel as well: http://www.h-dev.co.uk/product_info.php?cPath=78_169_293_488&products_id=25434
I've been to Cadwell a couple of times in my 350 and I love it. Its not that tight, run off is limited in some places. Angelsey is also excellent. Donnington is good too, don't like Blyton much though - too flat.
I've just seen the posts by ZEUS
ZEUS, I'm sorry you're not happy with the remap - I don't want people to go away disappointed with what we do.
Get in touch via email / PM / phone and we can have a chat and work something out
You can get a significant grove just from the seal. Heres an example of typical wear. They can often get deeper.
Happens to most cranks - I've got a load like it...
Knocking is usually the ball joint - the bushes don't often get as bad as the pics above, so no knocking until the arm comes away from the bush and start hitting the chassis etc.
We're only 1.5hrs from Birmingham - not in Horsham as my surname might indicate
We're running a group buy at the moment too: http://www.350z-uk.com/topic/85247-uprev-group-buy/
We're a Quantum dealer - I've not tried one of their maps on the 350/370 yet as I custom map all of them with Uprev on the dyno. I don't think their maps will work well if you have any modifications.
I've tried their remaps on a few standard diesel cars and a W8 Passat and they're really good.