When are you looking at the hop additions? Late hopping? Dry hopping? I just brewed a session beer with a 50/50 blend of 2oz Citra and 2oz Chinook as a hop stand. Only other addition was my FWH Magnum bittering. Citra and Chinook in even pairing is a nice combo on their own. How much do you want to feature the tropical fruit of Citra/El D vs. balance it out with the pine and spice of Chinook? I could see a 1:1:2 mix working to the balance end of the spectrum, however I do not have much experience with El Dorado so hopefully someone else can chime in.
One thing you can try is the
Bud Lite/Miller Lite hop experiment and play with different blends. Maybe even doing single hops per bottle and blending varying percentages from each bottle in tasting.