There are several different methods of ground wires.
1. You could just replace your existing ground wires with better and thicker ones.
2. Earth grounding - where all of your grounds go to your battery neg. terminal. This is what you pictured above.
3. Hyper grounding (?) - This is basically a daisy-chain from one side of your engine bay to the other.
I was going to do a homemade one a while ago. From researching it, most people said 8 guage wire is plenty and 4 guage was an overkill (though it looks cooler). 4 guage is more expensive and harder to crimp because of it's size.
That ebay one should work fine.