Right now we are not selling additional TG side panels and HDD trays separately for the Define R6. However, if we hear from enough of our customers that they would like to purchase these components we may be more likely to consider offering it as a retail product in the near future.
If this is something you would like to see please go to the Contact Us page on our website, select Product Suggestions, and in the message say something like "I would like to be able to purchase "X" for the Define R6 in the future". (Example is shown in the image below)
The more requests we get the more likely it will possibly happen.