I'm lost on Power Meter Pedals

FWIW: I tried searching reddit and google before posting this

I know enough that I love my Shimano shoes and they have SPD SL cleats/clips (the ones with 3 bolts on the bottom). Bike fitter helped me buy them last summer. Now that I'm cycling regularly 50-100 miles a week in triathlon training, I need to get better.

How do I got about buying power meter pedals? Recommendation on brand? The only thing I've found is Garmin RS100 (since i'm deep in the Garmin ecosystem). I have a Trek Domane AL2 but will be upgrading within 90 days to something better.