I have three pairs of Rudy Project Ekynox sun glasses with an RX insert that I swap between them. Additionally I have the Rudy ski goggle with a separate RX insert which is left in the goggle at all times.
To address your question I don't think you will want to put any type of glasses under ski goggles. People do it all the time and it works- but once you go to a dedicated RX ski goggle you won't look back!! The price of entry (goggle + insert + prescription) is pretty steep, but mine are 4-5 years old and on a per year or per use basis it's the best money I've spent as compared to other things.
As to my experience with the Rudy Project brand in general and the above mentioned products they are a TOP NOTCH company to work with. I've called them in the 11th hour to get things shipped and they are always willing to help. Great support with questions and concerns as well. They have a great lens replacement policy on sunglasses- so your investment is safe(er) as compared to other companies.
The Ekynox RX sunglasses are awesome- but I have a relatively small face so they may or may not work for you. My Dad has the "Kerosene" glasses with RX and they work well for him. I use mine regularly for Skiing, running, cycling, trap shooting. boating, fishing, driving and just general use in the outdoors and they work very well. You will experience some fogging here and there especially going from cold to hot or vice-versa. This is primarily due to the proximity of the RX insert to your face (this does take some getting used to) but nothing you can't manage or that's much different with regular RX glasses.
I had Oakley RX sunglasses prior- but did not have the ability to change lense colors as the lens on the Oakley was the RX. (No insert) I have 6+ different colored lenses for the Rudys and can customize to the sport or lighting requirements quite easily.
If you have other questions let me know, I'm happy to comment based on my experience.