From what I can tell, there are two main companies making antennas for the Italian 43 MHz CB market... SIRIO and SIGMA ANTENNE.
At the moment, SIGMA have three models...
This is a basic quarter wave ground plane. Note that the gain is quoted as 2.5 dB but that is probably dBi as opposed to dBd.
This is very much a compromise antenna and is aimed at those with restricted space. It is probably slightly directional in the direction of the small radials.
This is the five-eight wave ground plane and is made for 43 MHz. It's not obvious if there is enough tubing for it to made long enough to get down to 41 MHz.
The 1:1.5 VSWR bandwidth is claimed to be 1.64 MHz at 43.440 MHz.
I suspect that like the SIRIO, the smaller GP43 might be better in terms of surviving high winds and for general listening around the low part of the VHF spectrum (30-50 MHz).