If you lower the car I think you should be able to keep your stock endlinks front and rear.
However, with the stock ride height you would likely benefit from aftermarket endlinks as your stock pieces in the rear might bend. You should be able to keep the front endlinks no matter what your ride height as their are very few reports of the front endlinks bending and only with severe use.
There are reports of aftermarket endlink fitment issues with Cobb bars. For a mild setup on a street driven car I would consider the Kartboy rear endlinks as they have no problems with clunking.
Also, I highly recommend getting the "adjustable" Cobb setup. It will give optimal performance and fitment with the adjustable rear bar.