So after deciding for a while, this is what I finally chose the prizes would be

 

Category Winners (There will be 9 in total)

You each will get 

400 Karma Points *sorry it isn't a lot* Upvote to 2 stories of your choice Subscription to 2 stories of your choice

 

The OVERALL WINNER will get (1 in total)

1366 Karma Points *I know, really random number* Upvote to all stories, or if you don't have any, then 5 stories of your choice Subcription to all stories or if you don't have any, then 5 stories of your choice