Roger,
To add to my previous post, I'll wager that once you calculate the MAC of the F-18 stab and project the value onto the root you'll be at or near 43%. Just follow the diagram in the LMA-T (for turbine) guidelines. Also consider a strong reliable servo, 150 oz/in torque, to actuate the stab.
I presume you are going to use twin Byron fans converted to E-power. A buddy has done this with his Byron F-16 and the performance gain is fantastic. I believe he used a Hacker motor and 12S Lipos in the Byrofan. Good luck with your Hornet project.

Art ARRO