Since your usage list does not mention performance, I suggest you consider a 4.4. Because the 4.6 rims require wide tires it is not going to be very good in snow. The 4.4 is much more available and should meet your hauling needs. If it doesn't you add a few mods that will increase the torque. You are much more likely to find an X that is lower miles and has a complete maintenance history---perhaps a 1 owner driven back and forth to the store by a little old lady.

__________________
X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas