This is a hard question to answer. Because they are the same nationality they
may have a drink/s preference, which may contain specific type/s of liqueur/s.
I would ask the person that has selected you for this affair. If they say
there is than I would concentrate on stocking those type/s of liqueur/s.
In any case I would go to:
http://www.webtender.com/handbook/
Go to 2.1 under equipment and 3.1 under the Ingredients.
I believe a basic bar set up would be sufficient. But to be save I would have
another bottle or two of your basic liquors. You can always use them at the
next affair.