Understand the higher off the floor the less bass reinforcement. But also the top end dispersion will change as well. You may or may not like it, and the only way to be sure is to try it and see. Bear in mind stands for trying something like this can be anything. You can put them on a chair, a stool, a stack of books. Just so long as you understand what is going on and listen for bass and tone you will be fine. Then if you do like em higher this way you will know exactly how high and this will tell you what stands to shop for.
Another really big one to keep in mind, this sort of thing is really only do do with frequency response. There are also big improvements to be had from vibration control. So once you get speaker height nailed down then look into putting the speakers on Townshend Pods, Podiums, Bars, or if you can't afford those then Nobsound springs. Good idea to try these before doing the stands as you may well find so much improvement with those you stop even thinking of stands.
Another really big one to keep in mind, this sort of thing is really only do do with frequency response. There are also big improvements to be had from vibration control. So once you get speaker height nailed down then look into putting the speakers on Townshend Pods, Podiums, Bars, or if you can't afford those then Nobsound springs. Good idea to try these before doing the stands as you may well find so much improvement with those you stop even thinking of stands.