To add rear ground speakers i would need a stand which I actually have but would not look so good. Also i would have to hard wire cable in the floor coming out of the tile. Not so pleasing visually.
If you have or put in a large area rug you can run wires under that to your surrounds. I've used flat speaker cable in the past under rugs:
This wire is 16ga ... I paralleled the + and - together to get the equivalent of ~13ga ...
Also there are nice looking stands out there for under $100 ... like
this or
this