I have brined a few birds, both chicken and turkeys. If you want the turkey to taste more like a ham then I would brine it for about a week or so. Usually the longer the brine it the more it'll taste like ham, but you'll need to use a good brining agent, possibly Morton's. I got a brine mix from my local butcher, not sure what is in it, but I suspect it is close Morton's in contents.
Stephen