I think you're right to be cautious, I can't help with the legitimacy of the site but they appear to have a nice range of good quality bikes. I don't think the prices are to bad, assuming your based in the UK 1000 euro's is about £850.
It is a lot of money to spend on a purchase based on photo's, personally I'd rather see, inspect and ride a bike if I was paying that kind of price. I'd keep an eye on UK sites and Ebay, there's a seller below who imports some very nice Italian bikes, although he doesn't have anything at the moment.
http://stores.ebay.co.uk/Retrospective- ... les?_rdc=1
One of their previous sales:
http://www.ebay.co.uk/itm/colnago-vinta ... 7675.l2557
Also well worth keeping an eye on Retrobike or posting in the Wanted section of Road Bikes