Forgive me but the number of sectors for line Training (Flight under Supervision) is not down to whether or not you have GA experience.
It is standard JAR OPS stuff found in Part A.
It distinguishes two cases (With reference to what we are discussing here).
- First Officers flying types for first time
- First Officers undertaking first conversion course
Both require 40 sectors But the Director of Flight Training can reduce this requirement to 20. What he basically does, is to look at your previous experience and decides what you need as a minimum.
Usually it comes down to whether or not you have flown a jet before and what type of operations you were involved in (multi crew etc...).
The same goes for the landings. If you have similar previous experience, your base check will consist of a mini of 4 T/O and LDGs. If not then it is 6.