A good starting point would be to find an accurate recipe for a commercial IPA that you can buy and see what kind of hops that gives you.
Ounces per gallon without oil ratings is about as useful when making late additions as is ounces per gallon without alpha acid ratings when making bittering additions. Essential oils, not alpha acids are what matters most in late additions. Zeus with an oil rating of 2.5 milliliters of oil per 100 grams of dried hops is 1.67 times as potent as Zeus with an oil rating of 1.5 milliliters of oil per 100 grams of dried hops from a late hopping point of view.
For example, here is a complete Alpha Analytics hop analysis for an unknown variety that I grew this past summer:
While the GC Oil Profile report is complete overkill, the 1.81% v/w oil rating (1.81 milliliters of oil per 100 grams of dried hops) on the Certificate of Analysis is a critical late addition value that most hop brokers fail to include. All of the hops that Mark Garetz used to sell when he owned HopTech carried an oil rating, which made consistent late hopping a no-brainer.
I really never had any vendor show hop oil numbers. I noticed Yakima shows that with some of their hops. Makes perfect sense for consistent production. My favorite IPA uses about 1.15oz/gallon. My stand varieties are equal weights of Columbus, Centennial, Falconer’s Flight, Amarillo, Simcoe.
I dry hop with Simcoe, Amarillo, Cascade, and Citra @ 1oz/gal for 8 days.
Speaking of this, time to make another batch!
Here’s a link to an article that Glenn Tinseth wrote about hop essential oils for Brewing Techniques back in 1993 (man, I miss that magazine): http://morebeer.com/brewingtechniques/library/backissues/issue2.1/tinseth.html
Thanks for the link. Nice information on the hop tea.