The tockicos from my understanding also have a lifetime warranty as well. I would urge you to read the warrantys for each closely, most will not warranty lowering past a certain point. As I can tell the Gabriels are a close performer to the Tockico brand but not the same. It would seem both have their benifits but the Tockico is a bigger name in racing thus the higher price you see. Gabriels I imagine are not built as well as the Tockicos but have an advantage in that you can get them replaced under warranty around the corner at your local AutoZone.
To me it comes down to valving and which is going to allow me to get maximum traction and performance since I dont want to pay for a part and have to redo it latter down the road because I have more power. I recommend the tockicos.