It doesn't take a lot to anchor a TI. The lightweight
Cooper anchor I have works perfectly and that's what I would recommend. Just be sure to include a length of chain to ensure that it holds well.
The WAVESRX sand spike anchor you show looks like a beach anchor only. How would that prevent your TI from drifting into the sand?
Stick with the Cooper and you'll be fine. It's small, lightweight, and easily fits into the rear hatch. I keep mine in an anchor bag. You might even get away with using the smaller
Cooper Red Anchor.