Whilst I get that, the EK plates for example are thick metal which adds more support/structure - it will help compared to a flimsy stock option (I don't own the card so can't comment).
A pretty simple DIY means of doing something is just measure the gap between GPU and case floor, purchase some wood from your local B&Q etc. Like this:
http://www.diy.com/departments/dowel-moulding-t9mm-w9mm-l900mm/1240483_BQ.prd
Add some non slip pads to either end, prop up the sagging card end (should fit firmly if you measured well). That will probably cost you about £2 and take 5 mins and its pretty thin so will not impact airflow... Paint it to match etc etc.