i'd hang for 7 days max at the temp stated above (but thats just me), if you start to get a green tinge to the skin where the thigh meets the crown, dress em out.
if you can use your cone for the turkey all the better, your looking to cut the carotid (sp?) artery at the base of the head where it meets the neck. hang em up side down for about 2.5 mins and they should be drained.
if you've been culling and dressing your own Ross birds, apply the same to the turkey, only differance is how long you hang for, in essence, how strong a flavour you like your meat. the maturation (tenderness) will