what is the best quality /price garmin's product for me?

I wanna ask you for advice about my first fitness tracker. 
In a nutshell I love to do sport, in particular:
  • kayak (15% of my annual activity),
  • trekking (20% of my annual activity),
  • weightlifting (60% of my annual activity),
  • open water swimming during the summer (5% of my annual activity),

In general I wanna buy a fitness tracker that is able to give me the calories burned during the day with high precision considering my favourite sport just mentioned (in particular about weightlifting) 

 
I wanna buy a garmin wearable product, but I don't know which one to choose. 
 
In your opinion, what is the best quality / price garmin's product for me?
P.s I pay particular attention to the size of the watch because I have a small wrist. Therefore maximum case size of 40mm