salvage/reclamation yard

http://www.medussa.be/
Some distance from Bxl but the site is in English and they speak English and, to an inexperienced occasional visitor, they have got the world's biggest salvage/reclamation yard.

Couple of ironworks, but only in French

http://ferronnerie.janssens.a-vs.be/Pages/fer-forge-janssens.html
http://ferronnerievancampenhout.be/fr

There used to be some just outside the ring, but they've all moved further away as far as I know.

However, when I looked at the same thing some years ago, they were asking 1,000 euros/metre - and that in their original rusted state.

When at a big market near Krakow in Poland a couple of years ago I found an ironmonger who would make them to order following your design at 100 euros/metre. I can't help with the contact details, but that's the way I'd go if you can find a supplier online.
Transport shouldn't be a problem either given there are plenty of vans coming to and fro daily.

Good luck.

Worth looking at trick on line they show you all the stuff that's in them they have all sorts of odd bits and pieces.

Grr auto correct troc.com