Here's some possibilities from google maps. Don't think these have even 1000 ft of elevation change tho.
https://www.google.com/maps/dir/Scot...81!1m0!3e2!5i1
You can play with it and see what you like. My suggestion would be instead of coming back Thunderbird Rd, ride up the Skunk Trail to Union Hills and come back that way.
Have fun.