Porch/doorstep nosing

[baldeagle]

I guess it is called a 'nosing' as I've never heard it called anything else. I want to tile my outside porch but need to replace the nosing/step that overhangs out over the path. Where would I get something like this as they certainly don't do them in B&Q? I have some bits of bathstone that someone tells me I could saw and file to shape but it sounds a bit too advanced for me at the moment.
Any help appreciated. :?