This question is a few months old but I wanted to respond anyway, as we've been looking at the same thing. There are now some places in the ArcGIS Pro documentation where recommendations for different cloud providers are listed. See Cloud virtualization—ArcGIS Pro | Documentation and pages that are linked there.
Also, be sure to look at posts about ArcGIS Pro on the Esri blog - there was a new one this month about instance types in Azure ArcGIS Pro on the Azure NVv4-series
And, as usual, it might take some testing to determine which instance type is best for the work your're doing.
--Tim
https://www.geo-jobe.com/