I run 700c 32H wheels on my LHT with no troubles. I carry a light load on tour, but when I use my LHT as my errand bike I load up with obscene amounts of cargo and bounce all over town.

Not saying you should shoot for 32H wheels, but the fact is there is no specific # of spokes that are necessary. It really depends on how heavy you are, how much gear you'll carry and how bad the roads are where you'll tour.

What is more important IMO is how well the stock wheels are built up. I'd take them to a good LBS and get them properly tensioned or do it yourself if you can.