Pretty hard to trim a plan via the internet.
Adding guesswork to theory and dividing by unknowns - makes it all a SWAG at best.
Anyway - The ideal trim -for someone who actually uses throttle management will be different than that searched for by someone who flys full on or off only
I just converted my trusty old Senioria to electric ( Istuck in a setup which is pulling 300-500watts - depending on batery setup.)
Te REQUIRED thrust is a guess - and 300 seems like enough for the 4 lb /800 sq in setup.
prior to the change - the power was a 20 K&B Sportster on stock silent mufler and a 10x5 prop - turning 8000+
power was good enough
750 watts is about one HP so I think the 1/3-12 hp will do the job

On the Pilatus - the correct trims will also be based on power applied
guessing on correct amount of downthrust is a bit futile - till one decides on how it is to be flown
I love those models - everything purpose built -
You can't beat a big wing and lots of power.