Actually I just pointed out that you should not redirect product page to category page, Jere,y was the one who looked at your site and suggested to use options/variants...
And yes if you go that route and the category page will not exists anymore you need to use 301 redirect and send customers to different page if they reach the deleted page somehow, SE as well... but this is only if this category page will not exists anymore
redirect 301 /old_url.html
http://www.yourdomain.com/new_page.html
you can also use dynamic urls instead - your clean url or cdseo will pickup and convert them