Where do I find good product designers to hire that know SolidWorks

There is a Job Postings section here on the User Forum.

https://forum.solidworks.com/community/general/jobs

Check with your local user group leaders.

http://www.swugn.org/swugn/directory.htm

The best CAD users are well-occupied and well-compensated.  Keep that in mind when trying to "attract" talent.  Most I know aren't in a hurry to move and do the same thing for the same type of people for the same pay in the same environment.

Also, check the Linkedin SolidWorks groups.

... and let your VAR know... they might know of good SW users looking for a job in your area.

And don't expect much for a 6 month temporary job either.............