Rx goggles are hella expensive and are easily damaged or destroyed.
Since you already have a MX style helmet on the way, I'd suggest you get a good pair of "over the glasses goggles".
Take the helmet & glasses to a good bike shop and try on all they have.
If you didn't already have a helmet I'd suggest you try some dual sport helmets...they are full face but have more protruding chinbars and wider opening flip-up shields. Or remove the shield and have a MX helmet!
I have an Arai XD model and love it, on & off-road.
Oh, and welcome to TW Land!