What’s the best software to use alongside SolidWorks for creating multiple industrial design concepts quickly?

For example: I need to create 6 new design concepts for my boss.  Then take the winning concept, add the injection moulding features, and get it into production.  I've always done both conceptualiztion and prodution features in SolidWorks, but have thought maybe there's a better way. 

I'm a mechanical product design engineer, but interested to improve my industrial design skills in this way.

Goal:

- quick concept exploration

- easier to create interesting shapes than SW

- surfaces that can be brought into SW to create the production parts would be a bonus

- associativity:  if modifying surfaces in that program updates the SW file that would be a bigger bonus

There are a lot of programs out there, but want to pick just one to focus on learning.  What do you recommend?