You want a level-headed, experienced, seasoned ABM partner on your implementation team. Go shopping before selecting your ABM products and services . A package of onsite training, periodic coaching, software and workbooks. Ask for a proposal that meets your needs. You'll be glad you did.
All marriages are happy.
It's the living together afterward that causes all the trouble. Don't get caught up in the excitement of launching ABM only to later regret the partner you chose for the journey. If you simply use some common sense at the beginning, you'll be celebrating the benefits of ABM for years to come.