The apache series is comprehensive and should cover your technical modeling needs well so, depending on what you're into, you could try one of the more organic projects. Can't comment on the ones you've listed but just to add another one to your indecision, the dragon head is a fun one.
The organics will show you a different modeling method, as well....nurbs > poly > subD. The Apache uses poly/smooth proxy.
"Terminat Bora Diem, Terminal Auctor opus."