I'd address the seat before shorts. If you're getting pain or numbness, then you need a new seat. Stock seats are usually horrible, because it's the first and sometimes only thing almost everybody changes so why put a $100 seat on a bike that's just going to be swapped anyway? It's very important to have the right seat for you and everybody's right seat is different. Some people love the Brooks B17, while others absolutely hate them. I ride a Specialized Avatar 155, while a lot of people hate that seat. Even within brands, some people like certain seats over others. The Soecialized Romin is very different than the Avatar. You need to make sure you get the right size for your sit bones, then find the right seat FOR YOU.