Have you already purchased the drives? IF not,, why 80pin FC?
Yes your config should work, put each drive on its own channel, make sure you set each drive to be device 0. In the past, i used a few of the adapters, but the performance sucked.. but i think that is because i used cheap ones.
Put the adapter on the hard drive instead of the card. Usually with the adapters, they have a separate power cable going into it, so it would have to be on the drive. the 80pin FC drives usually get power from the backpane of the system