Many ale yeast go dormant below about 62-63 degrees. They may or may not carb up.
If storing them at 60 degrees is the only possibility, I'd add either 1/3 package of nottingham dry yeast at bottling (mixing it in the cooled priming solution) or a package of lager yeast as someone else mentioned. Not too many ale yeast will carb a beer when it's dormant!
If you had someplace in your house that is warmer, you could carb them up in an area that is room temperature, and then store then at 60 once they are carbed up. Sometimes a spare closet is the best choice.
