Help with an outing format

[KotOD]

I'm organizing an outing for my company. I'm trying to design it so that it's a non-competitive outing that will welcome all levels of golfers.

We've got about 25 people from our office -- 6 decent golfers, 10 duffers and 10 'others'.

Couple of questions:

1. What is the best format for a group like this? Scramble seems obvious, but if you know something better, shoot.
2. Should we make it a 'friends and family' outing to get more people involved?
a. If I do this, how do I avoid ringers? Yes, the dolts in this office are competitive enough to try to do this to a friendly outing.
3. Threesomes or foursomes?
4. How do I mix in the 'others'?