There is an active thread about fluids on nissan silvia. Im going to get penrite sin fully synthetic 75W90 for the gear box and the 80W?? for the diff. (Coming up to 90,000km)
You can get redline stuff from ebay from an online wholesaler -- but it seems too cheap. I wouldnt know if its the right shapped bottle with a fake sticker on it or not.
Oh and check how much of it you need too.. for the blu200 its about 1.5L for the gearbox and 1.2L for the diff. Ill get 2L.
As for getting penrite sin oils.... Save up your $$$ and then go online and register your email address with Repco. You get a 20% discount voucher for your next visit. Im going to spend a few hundred on Oils (engine diff box), radiator fluid, sparkplugs if they have the ngk, and maybe oil filters.