My wife and I were very lucky to travel on the Orient Express from Venice to Calais last summer for our honeymoon, although we're still paying it off. Absolutely fabulous but don't expect to get much sleep!
There are two trains: the blue one is the continental rake, the genuine Venice-Simplon Orient Express (that ran Venice to Calais with us on it), which loaded 16 coaches when we travelled. I have the formation noted somewhere because I would love to run one in N Gauge; the umber/cream rake is called the British Pullman that works the Folkestone to London Victoria section, along with various day trips within the UK.
The VSOE runs Calais to Istanbul once a year, taking a week and is about a £7,000 single ticket. They have their own website that gives details of the trips it makes: www.orient-express.com
The coaches sold by Hornby International in N don't match those in the refurbished train. There is an interesting book about the restoration available - I picked up a copy in the North Norfolk Railway book shop - although it is from the 1980s, it gives some fabulous details about the craftsmanship and attention to detail.
To see the 16 blue and gold coaches attacking a single track curved gradient in the Alps with two red locos on the front and one on the back is quite something! Such a shame that its a once-in-a-lifetime experience for me and I've done it already
Dan