Workstation Pro 14 is the current supported version for Windows hosts and Linux hosts.
Fusion and Fusion Pro 10.x is for macOS High Sierra hosts. Fusion 10.x/Fusion Pro 10.x are the current release for Apple Mac platforms so it is supported. So if you are already on Fusion 10.x, you are already on the supported version.
As for the maximum resolution on Windows 10 VM, it might depend on a number of factors (Mac graphic hardware, macOS display settings, is it scaled?).
FWIW, the maximum resolution that I see on a Windows 10 VM on a Fusion 8.5, 2880x1800 Macbook Pro with Iris Pro 5200 graphics is 3840x2400 (16:10 aspect ratio) and 3840x2160 (16:9 aspect ratio). macOS display preference set to "Scaled" and "More Space".