Stepping Up to MF, Seeking Expert Advice

Good Evening (for those of you in the EST at the writing of this message),

I am making the jump from 35mm to medium format, although I will still shoot with my D3 for the sports photography I do, but have decided to venture into still, portrait and studio imaging.

I am looking to buy a used HD3-39MS w/80mm 2.8.

Can anyone tell me if this is a smart decision, or if one would be better off with a new HD3II-31?

Just trying to see where $12K would be best spent, or if neither are good entry level cameras.

Thanks and look forward to any assistance,

Steve R
Durham, NC