After Jon mentioned on Thursday night about a source he had found for steel bases I decided to go digging further and found...
I reckon this must be the same site he was talking about but anyway, there is the link above!
There are a lot of base sizes available here and I do like the idea that the bases are galvanised and primed black. With the base already magnetised it's a no brainer for me and I will be placing an order soon.
I was also impressed by the customised measuring kits for different rule sets, a novel idea!