We want to have. A living trust , we have been advised to not have a joint trust but two separate trusts, New Jersey sound right

There is no such thing as New Jersey probate tax.   If you have out of state property, you might consider putting it into a trust to avoid having to go through probate in the state where the property is located, but there is no NJ probate tax.  There have been some changes to the New Jersey estate taxes, and if you are leavling assets to a more distant relative or someone not related to you, there might be inheritance taxes.