Lately Q4Wine has been my favorite Wine GUI since it's very flexible and allows setting up and managing prefixes with specific configurations. Also wine-ge-custom is a custom build of Wine based on Proton meant to be used with non-Steam games outside of Steam.
To make a prefix use a certain Wine build first it needs to be added under
Tools -> Wine Version Manager
and after that is done in the Prefixes tab it can start being assigned to them.