Sinkieland should emulate Hong Kong's style of politics, the Brits had a few more decades to refine the process prior to 1997.
Three groups of MPs or representatives:
1) Municipal. You jaga your own town council's matters, you do the meet-the-people sessions, listen to complaints etc.
2) Legislative. You write bills and make laws.
3) Executive. Your ministers, the next PM is picked from this pool.
These three groups are separate.
Which means the GRC system must be abolished i.e. you no longer need a minister to 'anchor' a particular GRC. That also makes gerrymandering obsolete.
Residents in 'buffer zones' may from time to time choose which constituency they wish to join. For example, Sunset Way can choose whether they want to join Bukit Timah or Clementi. They will have a 'referendum' and vote to decide.