Mavic 840 rear mech Compatibility

Hi all. I want to fit a Mavic 840 rear derailleur to my bike and am deciding on what brifters to use? Dura Ace 7700 (all metal levers) or Campag 8/9 brifters (all metal levers).
I know Mavic works best with Shimano and have heard of people complaining of shifting with Campag brifters and Mavic rear mech.

If I fit a shimano rear cassette with campag spacers (Top mechanics back in the day used to do this for perfect shifting) and use Campag 8/9s brifters will it be ok?
Or should I just use Dura Ace 7700 9s brifters with the Mavic 840?

I would prefer to use Mavic 9s 1997 shifters but Dura 7700 will have to do if thats how to achieve good shifting with a Mavic 840 rear mech.

Whats my reason behind mixing groupsets? I want to do a full Mavic groupset build on my retro LOOK bike and Mavic didnt make cable operated brifters.

Cheers

That comment about mechanics fitting Campag spacers was in regards to a MAVIC cassette.
Just wondering if it would have the same effect then with a shimano cassette and Campag record brifters.

I use a rear 840 mavic derailleur on my Merlin Mountain. The shifters are 8S shimano dura-ace, used as thumbshifters on Paul collars and the cassette is 8s XTR. It works very fine and very precise.

About 9s, I don't know

The above setup should work with a 7sp cassette and 9sp Ergopower levers as the Mavic 840 was - I think - Shimano compatible so a "Shimergo" mix as above ought to do the job. My CX bike had an 840 with 10sp Chorus levers (alloy) and SRAM PG850 8sp rear Shimano-pattern cassette and all worked well. Until the mech ate too much long grass during a race at Hillingdon and died spectacularly (thanks to the Ergal mech anchor bolt ripping out of the rear dropout - its successor is a short-arm Sachs Quarz with a chrome steel bolt made of sterner stuff).

David

Yes the 840 will work with 9s.
If I use 9s Ergopower, what rear cassette setup would be optimum?
Shimano with campag spacers or shimano with shimano spacers?
Im leaning toward shimano with campag spacers.

Cheers