Honestly the answer to this question is going to be based on whoever happens to be the best salesman on that particular day. Though IIRC S1850M is either an improved version of SMART-L or simply the Thales brand name for their particular APAR set (APAR is a broad classification of radar type, not a specific set or brand). Or maybe Sampson is the Thales brand name for their APAR set; either way the combinations you listed are both Thales and one or the other would be available.
S-1850 is the licenced production version of the SMART-L. the differences are mainly in parts which can be produced in britain and things like that. specification wise it is about the same.
SAMPSON is not build by thales.
just wanted to see that corrected