With a P60 the dry weight will come out to 19 lbs even, with the K80 it comes out at 20 lbs even, best choiyhere is the K80 or K85, throttle management is the key here, I fly mine at just above half throttle and full throttle for climbs only, at level flights full throttle doesn't help because of the drag been created at those speeds ( the wing core is 3.5 " thick )
The K80 is super reliable and 1/3 cheaper than the P60SE and the P60 burns way more fuel than other 60 size turbines.
With the K80 the airplane comes out 1 pound heavier but you gain about 5.5 lbs of thrust and it burns just a tad more fuel than the P60.
I replied to your pm with links to the Reaction TOs and landings with both engines.