Tim (I presume), your dosing-math is flawed if you're calculating thousands of dollars worth of Sonar to treat 12 ac-ft of water for EWM.
Assuming your pond has little or no flow-through (static water), 3 qts of SONAR
GENESIS should prove quite ample for EWM in 12 ac-ft. Depending on your selected source, 1-gal of SONAR
GENESIS should cost less than $450. You can't beat the residual activity that it provides under static-water conditions, nor the ease of application.
I don't like that math one bit! 12 acre feet is thousands of dollars if applied like they recommend. I may use the Diquat and Copper Sulfate mix first on one area and see if that gives the desired results.
You can buy sonar in quarts. Plan on treating it again next year or the 2nd year. Seeds which have been produced this year will lie dormant and sprout next year and thereafter. You will eventually need to retreat due to return of milfoil or some other weed. Do the math for your costs and amount of each herbicide needed. Aquathol superK is a granular and SonarAS is a liquid.
