I'm actually a big fan of St. Germain. My only issue with recommending it in this case is that it is a fairly.. nuanced flavor. For example it mixes well with gin but does not alter the flavor SIGNIFICANTLY. Definitely noticeable, but the OP may be better off going for something a little bolder, this early in his explorations. Though of course, the subtle flavor may be a good entry point, so, to each his own.