I’ve set my sights on the Diamond BB-7V. The reviews are mixed: from just a dummy load to great. At this moment I’m still considering it, but thinking about making a few adjustments. Arie PA3A advised me to place chokes on either end of the coax; at the receiver end and the antenna end. This should help picking up less noise by the outer shielding of the coax. And secondly, I think about making two counterpoise wires: one 1/4th length for 80 meters (= 20 meters) and 1/4th length for 40 meters (=10 meters). This might help in improvement of the transmitting on those high bands. This idea is thanks to: https://www.onallbands.com/guide-to-no-tune-antennas-for-ham-radio/.
If you have other ideas of suggestions, please let me know in the comments!