Re what I'm using, let me preface that I usually recommend to folks new to e-codes and Euroheadlights to start with the standard 55/60, because the improvement in lighting solely due to the improved optics is so vastly better that I've found many don't even desire more wattage.

However, especially because we regularly go to Maine for spring-summer-fall weekend vacations -- usually at night -- I like to be able to light up the road on the empty Maine highways and secondary roads (my big fear is hitting a moose :-). So I go to higher wattages (with heavier wires and relays, of course).
And, most important but I forgot to mention this earlier (I hope this catches your attention), some folks have reported melting plugs (the wire socket for the H4's) with very high wattages -- albeit usually higher (e.g., 120 Watts) than I use. I've switched to a certain model of plug sold by NAPA stores which is heat tolerant -- they sell two types, but the more costly one is the one that's heat resistant. I recommend them to you.

My '84 with quad rectangular Cibie e-codes (which used to be our regular "ride" to Maine), I'm using 75/80 in the hi/lo lamps and 100's in the high beams. Although we no longer use this as our main "vacation" car, I still use this one as my commute-to-work and run-errands car and I've kept the same bulbs in them. By the way, they've had a remarkable, mind-boggling lifespan -- I've had the same bulbs in this car for about 18 years (as long as I've owned it), despite that I use the car a lot in the dark (I commute to work in the dark, and in winter I return home in the dark, too).

In my two '93s, with Euroheadlights (one with a poor DJAuto-brand set, and the other a Volvo/Cibie-brand set), I'm using 55/80 (or 60/85, I can't remember) H4 bulbs in the former (my wife's commute-to-work car) and 80/100 (or 85/110, again I can't remember for sure) H4 bulbs in the latter, which is our current "weekend/vacation" car. [It was going to be my daughter's car, but she's moving to CA, so she'll have to buy a CA-certified car, and hopefully a new Volvo, when she goes there.]

By the way, just some comments, especially meant for other readers who have not yet converted their '86-on car's headlights....
Not to knock your choice in headlights (200mm rectangular) which you've no doubt fabricated into a nice customized installation, but they (along with my own '84's 160mm rectangulars) have never been considered to have 'great' optics, despite that they're made by Cibie -- so somewhat higher wattages are more apt for these.
The flaw with rectangular headlamps is that it isn't round, which is the ideal shape for an efficient parabolic reflector to collect the emmissions from a filament. If you look at any rectangular lamp, you will see that the rear is really a hemisphere with the top and bottom lopped off (analogous to the Earth with everything north of the arctic circle, and south of the antarctic circle, lopped off). Thus, the reflector can only capture a portion, albeit it still major portion, of the photons given off by the filament. Even the Euroheadlights are faulted in this, although a tall housing used for '86-on cars allows a near round shape, and the "lopped off" top and bottom is less (in proportion) than what is lost in the rectangular 200 and 16 mm lamps. The best shape being round, the 7 inch round lamps, larger and therefore deeper to better collect as many photons as possible, are still best, followed by the smaller 5.75 inch rounds in quad -- although smaller and less deep, and therefore less efficient photon collectors, by having 4 lamps (in high beam) they make up for their deficiency and undoubtedly surpass the 7 inch lamps in high beam, when all four can be used. The 7 inch round is still best in low beam, however.