Out of these brushes on Ebay, which are good for Shelties?. I have a 6.5 month old and a 5 month old. I need a pin and slicker...I'm afraid my Petco "four paws" brush has completely destroyed their coats...as their coats are both curling upwards now and feel brittle. 
http://shop.ebay.com/i.html?_nkw=all+systems+brush+&_cqr=true&_nkwusc=all+sysems+brush&_rdc=1#ptm110729531662
http://shop.ebay.com/i.html?_nkw=all+systems+brush+&_cqr=true&_nkwusc=all+sysems+brush&_rdc=1#ptm110729531662