Hi, I was thinking of the possibility, just in the case of box speakers and not with corner horns, of Paul building it in brick and mortar (just like two fireplaces/bass boxes he would add to the Room, frnt panel in wood - also space for the highs units on top at project distance.)
Just an idea, because after that you can't move them, but you can always make the box smaller (or larger if you demolish) and you can not go on "tour" way of saying. I don't know if the garden allows such an option. Best Regards.