The biggest step in advancement is to go to a full fuselage airplane. This gives better rigidity resulting in better aerodynamics, and more consistant engine runs. A worn out statement is that "I am not ready for that airplae" when the fact is that in most cases the profile is holding the person back.
That said, the Classics offer the best all around solution. My personal favorite is the "J.D. Falcon", which has been very successful, it is as good as it gets!
To this you can add Kostecky's "Talon", The "Roadrunner", the various "Noblers", "Skylark". "Jerseyan", "Cavalier" and many others.
If you still insist on a profile then, "Profile Road Runner", "Profile Cavalier"
While the straight wings are easier to build, the improved performance of tapered wings is much more desirable.