This may not be quite what you're looking for, but how about this Elvish greeting: "Anar kaluva tielyanna!" (Meaning, the sun shall shine on your path.) This phrase is from "Of Tuor and his coming to Gondolin" in the UT.
Of course, if you have the time and energy, browsing through
Ardalambion's Quenya courses and writing your own sentence might be cool.
