Just a final update to this, I'm not sure why my allowed impact changed when I gave the land to the group, makes no sense, but I was able to do it by deleting my skybox (I wasn't using it anyways), which lowered my land impact enough to keep the house intact.
Permissions are working correctly now, thanks all.
As for the stream board, I'm considering just using that next time. I'm looking at this one at the moment: https://marketplace.secondlife.com/p/SHX-SHOUTcast-board-Club-DJ-system-SRC-F4s/13064181