Hi there,
Sorry about your loss, that's very unfortunate. I've read of a few people who have kept them communally, but it's not as clear cut as emps are.
As for H. trilineatus, I couldn't find very much info on them, but here is a pretty good guide:
http://www.venomlist.com/forums/index.php?showtopic=19499
The best I can suggest from the little I know of them is to provide adequate space, food, and hides. Some members used 50/50 sand and cocofiber while others look like they just have it on sand.
I think it'd be fine to move into your V. spin setup.