I have some (Sorry, I can't post pictures at the moment:( ) that use panels. They have hexagonal symmetry, with 6 segments that fly apart when the decouplers are activated. The piece inside the fairings is standard 1.25 meter, and the rest of the rocket is the Rockomax size. There is an Aerodynamic Nosecone on the top, which flies forward (attached to an upside down decoupler, with Sepatron motors on it.) when the rest of the fairings go out. Dual-split fairings are harder, they usually need Sepatron motors. But small probes are a good size for these. I currently have a "Weather Monitoring Satellite" (KerbSat) with dual fairing sections.