Well, I'm not in the UK, but I've been known to give a good price for millwork from time to time. If you're willing to pay for overseas shipping, I imagine I could make you a set of door moulding from any US domestic hardwood for much less than you might expect (our wood is not quite as expensive over here, and a door's worth of moulding in that profile wouldn't take me long at all.)
So if you can't find anything on your side of the big pond, e-mail me at prometheuscharter.net, and I'll work you up a quote.