Hi John,
Peco do suitable track. I will use it when I get round to my layout.
Here are some links for you:
Supplier: EDM Models:
www.ngtrains.com
Publication: 0n30 Annual (from EDM Models)
Slim Gauge Circle:
http://www.slimgaugecircle.com/
7mm Narrow Gauge Association:
http://www.7mmnga.org.uk/ Excellent 0n30 handbook.
Hope these links are useful.
Best wishes,
John H-T.