I guess that I should put in the obligatory plug for Fischer skis. They are very well made and as bomproof in their construction as you are likely to find in a pair of skis. 155-160 sounds right.
You may want to consider gettting your son to take the lead in the search for skis with a budget (and possible veto) set by you.
He might begin with the Epic Ski Consumer gear reviews (and Epic Ski may have a new member.) There are a number of excellent ones posted.
He can read the magazine reviews for what they are worth. Ski Canada, Ski Press, Ski and others have reviews available online. Other useful review sources include www.footloosesports.com
. Have him look at what the lighter weight reviewers are saying about a particular model. Take him to visit several real ski shops and talk to the staff there.
A lot of the joy of aquiring new skis lies in the hunt. It will be a good learning experience for him and he will still appreciate that the skis are a gift from you.
Just my 2 cents.