Red dot sight for possum shooting?

I'm looking to fit a red dot sight or similar to my PCP specifically for night shooting possums (at some point in the near future).  From my very limited knowledge, they will be sitting up trees typically at a range of around 5-20m.   For this purpose I'm thinking a decent red dot sight and a good miniature LED torch fitted to the underside of my gun would be a good combination.

I'm keen to hear any recommendations regarding this setup or better, and for suitable equipment.

Hi Pete.

Spent some time setting the gun up today so I can go hunting with a work colleague who has been shooting big numbers of possums on a customer's property.  I'm using a Holy Warrior S1, a very good clone of the Eotech but a red dot rather than a holographic display.  All was going well sighting it in at 20m, but I then started struggling with the adjustment and just before I packed up I noticed the silencer was loose.  Took a look for nicking and found that plus a lot of lead particles so that explains the problem.  at this stage the sight is very nice to use, a nice clean illuminated reticle and I can get a good view with my glasses on.

I was planning to do some 10m indoor sighting tonight but for some reason most of my flouro lights have decided to stop working.  Yet another job to do!

Cheers 

I should have commented on that.  The haul is from one nights shooting by my colleague and a couple of mates, all using powder burners.  I hope to go out with them in a couple of weeks and see how the PCP compares.

I'm new to this so I'm not sure what you mean by "What distances does the one (red dot) point of aim cover?"