Get all from the Traders on here or gaskets and seals direct from Nissan and the bearings from here: http://simplybearings.co.uk/shop/index.php?cPath=4747_4514&gclid=CO-t_77r7coCFTAz0wodVqUHwg
This is the way to go as you have to many questions.
There are a few in your area, however if you are ever up in Perth, then swing by and I will take you out in the 666bhp 350. which has a twin plate ATS Carbonetic fitted.