The king of the instruments during the Renaissance, of course, was the lute. But acquiring one of these would take a bit of time and would undoubtedly be quite pricy. Also, they are just a touch on the fragile side, so they won't take much knocking about.
This instrument, the psaltery (NOT a bowed psaltery, which is a recently invented instrument), is ancient. They were falling into disuse around the Renaissance, but there were undoubtedly a lot of them around. No one could questions its authenticity.
A harp would be quite safe in terms of authenticity.