What brake cable (or kit) do I need to do this?

I will have to bleed it right?

if its mechanical it wont need bleeding but I dont think there is a mechanical XTR brake so you will need longer hoses and some fluid and you will have to bleed it

Yes, longer hose (surprise surprise!) and bleeding.

CLICKY – Something like this is for you want to completely replace alternatively most hose is availble for about £6-7 per metre.

As for oil just got to local motor factor and get some dot 4 or dot 5.1 brake fluid

shimano use mineral oil not dot fluid so don't use dot fluid – you will ruin the brakes

and you will need a little yellow goodridge tab for extra too cool for school points.

You'll probably need a new olive and insert too.

Do you mean hose?

If you do then get some compatable goodridge hoses and a small bottle of mineral oil from CRC and the like?

http://www.chainreactioncycles.com/Models.aspx?ModelID=2938 – goodridge hose

http://www.chainreactioncycles.com/Models.aspx?ModelID=20424 – connectors – not cheap – check the fit your version of XTR?

http://www.chainreactioncycles.com/Models.aspx?ModelID=29899 – mineral oil