Honestly the Amazon antenna will probably do perfectly fine, I might go that way for simplicity sake.. maybe I'll build an antenna too and do some a/b comparisons.

The 90 degree angle doesn't hurt performance inherently, it only hurts it because it puts the antenna right next to the body of the radio, blocking some of the signal, and detuning the antenna slightly as well. So you're still better off putting it vertical 👍

Also in case you didn't know, those antennas are vertically polarized. That means when the tip is pointing up to the sky, the signal is coming out the sides going off towards the horizon. That's the best way to get a signal out/in. Holding it sideways will create null points from the tip and base of the antenna, and also send half your signal into space and the other half in the ground 😁