These are my choices, and I think most of them look they would either belong to Lucas or Sami or a mix of their features to some degree except for maybe the first one. All are good actors.
Jake Weary (ex-ATWT) - age 16
Sean Marquette (ex-AMC) - age 18
he looks better on IMDb - http://imdb.com/name/nm0549826/
no pic I can link too
Paul Iacono (ex-AW, ATWT, GL) - age 18 - see http://imdb.com/name/nm1476591/
Tyler Hoechlin (7th Heaven) - age 19
John Patrick Amedori (many shows in primetime) - age 19
http://imdb.com/name/nm0024511/
Shawn Pyfrom (Desperate Housewives) - age 20
Karl Girolamo (ex-ATWT) - age 20
I like any of them but Amedori might be a natural progression up of the Gerse and what he might look like older. In the roles I have seen him in he is pretty good too. But I like any of them.