This is a significant piece of work in order to consider both tax and legal issues.
CGT and IHT will both impact decision making for lifetime trusts.
Will trusts will negate CGT but IHT on estate.
IIP or DT trust options will depend on what the settlor wants the beneficiaries to have.
etc etc
A lot more information and time would be needed to give proper advice. I would suggest seeking specialist legal and tax advice.