Are surrounds ok high on the wall? Close to ceiling, or keep it at 24" above head?

My apartment is odd shaped, and I doing a 7.1 setup. If my 2 side surrounds stay on the wall, at the reccomended 24" above ear level mark, then they will be 3 feet off from each other (across room that is). I could move the the speakers up higher and hit a beam that runs through the middle of my apt, the speakers would be even, but they would be closer to the ceiling, which is 5 feet above listening level. Any suggestions here? The guy at the local audio store said the lower idea would still be ok? Let me know what you think! Thank you very much!

Ok, I posted a picture to make it easier. That is the beam up top that I am talking about. I can either put my side surround on the vertical part of that beam, and the corresponding speaker will be 3 feet off (acroos the room from it), or I can put the speaker up high, along the horizontal part of the beam, and have the speakers be even with each other. Basically, if they go vertical they will be 2 feet above ear level, if they go horizontal and higher, they will be 5 feet above ear level and pointing downwards. I hope this makes sense? Thank you for looking and the advice!

Maybe I should just ask this also: Will my surrounds sound any different on a higher level, possibly pointing downwards, or should they stay at 2 feet above ear level?