Spider Colombo Cornalux B22  

yes but not cheap
I found this source
http://www.surrounding.com/Products/Light_Bulbs/Spider_Light_Bulb_Cornal...

Really expensive...
...but thank you!

It would be easier and less expensive
for your US customer to buy a step-up transformer and use the European bulbs. Maybe safer, too.

Which transformer is needed?
How big is a transformer? And where to hide a transformer on a ceiling? It doesn't look very good...

Ceiling mount
I assumed that you were selling a table lamp or floor lamp, so I did not imagine that ceiling mounting would be necessary.
A small transformer typically weighs between 1kg and 2kg, and would be packaged in a rectangular case approximately 20cm x 8cm x 8cm. Your customer might find an even smaller and lighter transformer -- maybe half that size -- especially if he needs it only for a lamp (appliances require more current, especially at startup, so transformers for appliances must be physically larger than transformers for lamps only).
Here is a typical transformer, along with a link to it on Amazon (note that I have no experience with this particular device and so cannot recommend for or against it; I am simply showing it as an example):
http://www.amazon.com/dp/B001TPZ294

Thank you very much, fastfwd
I will give the information to my customer!