For the chain, our Nelly reccomends Tsubaki.
Are you after a quick change rear sprocket? I have the Talon stuff and changing the back sprocket is really quick and easy, like it says in the tin really! Only really neccessary if you change you ratio frequently, but also with the Talon carrier (don't know if it's the same for others) is that it captivates the cush drives so they don't shift out and grind themselves away on the swing arm - not a common problem, but it's not unheard of.
For a QR carrier, make sure there's not a shortage of theadlock... you wouldn't want the sprocket retaining bolts falling out on the M27, hypothetically speaking
!!!