In reply to Martin W:
Unfortunately Merlin don't have the groupset I'm after in stock, nor do they offer the specific options I'm after. I don't want to have to end up chopping and changing bits of the groupset, that rather defeats the object IMO!
One of the German discounter sites does have what I'm after, but at a significantly higher price than Vanilla Bikes advertise (but can't so far supply). For that price, there are places I've already researched where I could treat myself to 105 rather than Tiagra. But I don't really want to pay that much anyway.
I think I'll give Vanilla Bikes the benefit of the doubt for a bit longer just now, but I'll definitely cancel the order if the delay starts to get silly.