I went SS over the summer, with 32/18 on a On One Inbred 29er. I'd like to change this to 32/20 as I'm finding I am totally ruined at the top of climbs, although I'll probably switch back to 32/18 for the longer days in flatter areas.

I saw in one thread that KMC Z610 HX chain for SS. The linked one is 3/32", the the chainring I'm running is a On One Strainless jobby, which claims support for 1/8" and 3/32".

So, can I use a 1/8" sprocket, such as the Halo one with that chain? Otherwise, can anyone recommend one for no more than £15?

I want to replace the chain too, as my existing one rattles, and that really get on my nerves.

You should be OK with a 1/8" sprocket if you can get one, though most are 3/32" anyway. Chainrings can be either IME.
3/32" < 1/8", so a 1/8" chain will work across both, but a 3/32" chain (i.e. 8sp) won't work on 1/8" rings.
I use Sram PC7X chain. Have a look on Velosolo for sprockets: the Andel ones are the same as Surly. Over your budget, but long lasting and with a wide bottom that doesn't eat into your freehub. http://www.velosolo.co.uk/shopsingle.html

a 3/32 chain is too narrow for a 1/8 sprocket it wont fit.

If the sprocket tapers off towards the tip, which they tend to do, it might rest on top / jamb its self onto the teeth but it wont work

Get a 1/8 chain if you want to keep your sporcket, such as this
http://www.charliethebikemonger.com/kmc ... 8-42-p.asp
the Z510

*edit. If its a true 1/8 width*
*edit2. Sorry, I see you want a sprocket and a chain, in that case I would go with ians choice of sprocket and either the z610 or Ians choice of chain.
Its worth noting that Ians done a hell of a lot more SS miles than me, so his chain choice should be sound.

1/8" also appears to actually last forever. I have a couple of WTB laserdisc sprockets which with a bit of dremelling I could make fit on a Shimano freehub and not just a WTB laserdisc one. I was well impressed - especially given the price. I don't appear to be able to find them anymore to fill in my missing sprocket sizes

Excellent, thanks all.

I think I'll just pay the extra and get one of the Andel ones then, in the long run I'd like to be able to keep this bike SS permanently, so it'll pay for itself eventually Went with the 1/8 KMC chain in the end, just to save gaffing around with two parcels. Can be nightmare where I live sometimes.

Looking foreword to getting some SS miles in again now.

http://superstar.tibolts.co.uk/product_ ... cdvbiaoap6
The SuperStar ones are only £8 so affordable enough to buy a few different sizes. Wide base too

The SuperStar ones are only £8 so affordable enough to buy a few different sizes. Wide base too

Got one of those currently, it's elliptical (common issue with them) so the chain repeatedly jumps off on anything remotely rough.