Z690 or z790

Hi everyone

I am thinking of upgrading my pc.

I have i9 9000 with 32gb ddr4.  

Deciding on the cpu, and the ram, was easy.

But when I look at the motherboard options ...its a nightmare.

Originally I thought anyone of these;

gigabyte arous z790 elite

Asus z790 f

Msi tomhawk.

Or similar would be ok. But having listened to few YouTube etc. It seems that some z690 are equally good.

My reason for upgrade is purely to see an improvement in msfs2020.

can you please share you suggestions and experience. 

I am trying to do the upgrade as cheap as possible.

Many thanks.

Qas