Alternatively, if you aren't able to find one, or not prepared to put your faith in them, have be bike delivered to the
Halfords store in the box and build it yourself, or, take it to a local bike shop to get them to build it for you. Or at least get it checked over in the LBS if not certain of the quality of the in-store work.
(and I'd do that if buying from
Evans tbh - though I'd go down the DIY route)