Would have to change the rear derailleur too then.
Might end up being the same amount as just buying the SRAM hydro shifters. That being said, I do prefer Shimano so maybe that's a better option.
I'm also considering cable pull hydro calipers such as Juin Tech.
Can you not just go Shimano for the brakes? There are some good deals floating around on grx and 105 at the moment.