http://images.google.com/imgres?imgurl=http://www.tpub.com/content/aviation/14310/img/14310_204_1.jpg&imgrefurl=http://www.tpub.com/content/aviation/14310/css/14310_204.htm&h=784&w=406&sz=46&tbnid=txOFfpgz7n4J:&tbnh=140&tbnw=73&start=12&prev=/images%3Fq%3Djet%2Bblast%2Bdeflector%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DG
and here is a nice build in 1/48.
http://members.tripod.com/scottsmodels/a-6e_enterprise.htm
While there are no dimensions given on these, the build does give the size of the base so you could estimate from there.
Another possibility is Dragon makes a kit in 1/144 with an F-18 on a carrier deck with the JBD. Would be real easy to scale it up from that (and the kit isn't that expensive either).
Good luck,