How heavy are the speakers?
There are a significant amount of wall mounts available on the market, from Cr@p-@$$-cheap sh!t to a Hundy per speaker and more.
K&M make very nice mounts that are expensive, but if installed properly can support a lot of weight. Some good designs also have clamping grips that will hold a speaker from the bottom and allow you to swivel and tilt.
Beyond everything else... as mentioned above, a combination of Wall Stud with Lag screw and good quality anchors is important.
Regarding the orientation of the speaker and potentially inverting it...
You need to know whether the speaker produces a tilted FR on the vertical access... A 2nd or 4th order XO is usually safe (maybe), but 1st or 3rd orders tend to tilt the FR, for example. This can be a serious rabbit hole fraught with thickets and other issues.
Unless you know for certain, it is safer to not play those reindeer games.