He looks quite a lot like ours (although this pic isn't that good a demo it's the only one I have online):
I think (after much trawling of planet catfish) it is a sailfish pleco - the LFS referred to it as a leopard pleco when we bought it too. Here is a link to some info: pleco info
We got it at the same time as a common pleco about a year ago, they were both 2inches at the time. Just gave our common back to a different LFS (have moved house) and it was over 12inches. This pleco is about 8inches at the moment.