Well.. I have to choose now.
I have contacted several different China laser-manufacturers and have to make my decision now.
Viasho
Beam Quality: < 1.2
Beam divergence: 1.2-2.0
Beam diameter: 2.0-3.0 mm
Modulation : 30Khz TTL / 10Khz Analog
Least expensive
Rumzing
Beam Quality: < 1.8
Beam divergence: <1.2mrad
Beam diameter: <2.2mm
Modulation: 30Khz TTL / 15Khz Analog
CNI Laser
Beam Quality: < 2.0
Beam divergence: < 2.0 mrad
Beam diameter: +- 3.0 mm
Modulation: 10Khz Analog
Most expensive
I found some posts about the different manufacturers on the forums, but maybe this list of specifications and price indications can have influence?