Having been caught out recently when a web site I launched displayed perfectly on IE, Firefox, Chrome and Safari on Windows but was corrupted when viewed using Safari on the Mac
See tutorial here: https://www.wikigain.com/install-macos-high-sierra-virtualbox-windows/
You will get the latest Safari.
You don't need to pay for those online services!!!
Use these vbox settings to increase resolution and memory, but it is still very laggy and slow:
cd "C:\Program Files\Oracle\VirtualBox\"
VBoxManage setextradata "macOS" VBoxInternal2/EfiGraphicsResolution 1920x1080
VBoxManage modifyvm "macOS" --vram 256