For now, I'm thinking like this:
Weight of votes:
Didn't participate - 0.5
Participated once - 1
Participated twice - 1.5
Participated 3+ times - 2

Regarding the format, I absolutely don't see the point in holding it in 2 rounds. We don't have 10+ options. It will only prolong the process. IMHO.

I'm not sure if a multiple-choice option is needed. I think it is. If a person wants to participate and 2nd place is equally acceptable, why should they have to choose?

In short, I'm waiting for reasonable suggestions. What does everyone think?