Upgrading From A Monarch R

Looking for some advice on the best and suitable rear shock to upgrade from my current.

I have a Vitus mythique VRX 2021 with a rockshox monarch R rear shock. It’s ok but want to be able to get better pedalling performance out of my rear shock due to the style of riding I mostly ride.

Ideally I’d like the shock to have a full lock out function.

Any one provide any advice on a suitable replacement?

Thanks
D