Check with a turfgrass specialist or a real nursery for suggestions. Your parks department or any golf course will have a turf person that will help you out. University, County or State may have an ag extension turf person. Call a sod farm or hydoseeder. Find out what they would suggest planting in terms of a turf mix. Be sure and mention your shady conditions.
Before committing to sod, do look into hydroseeding. It will save you quite a bit of money over sod and will establish faster.
One thing you have to be aware of with sandy soils is that you will have to water and feed more than with other soils. When you prep the area for planting---sod, hydroseeding or traditional seeding---try folding in soil ammendments for water retention. Think through how much turf you really want and consider alternatives like nice colored and textured ground covers.