A better question might be whether the French vertical cell launcher can handle larger weapons. An Iranian nuclear threat is inevitable with the current impotent foreign efforts to stop it. The Saudis may be looking for an anti-ballistic missile option. SM-3 fits in the Mk 41.
The French Sylver system does have a long variant, the A70. However, its production volumes seem to be very low (probably only the French navy for cruise missiles), so cost would go against it.
http://fr.dcnsgroup.com/wp-content/uploads/2014/10/FP_SMA_Sylver_GB_DEF.pdf