Is is not possible to wall mount the 52s with some space behind them.

I use 52s with a REL Strata 3 sub and it works very well IMO. Going to tiny speakers must compromise the sound surely, unless the room is very small.

I've got a small baby at the moment but when she starts to walk in about six months I'm going to wall mount the 52s for safety (of baby and speakers!).

If you can't find suitable wall mounts then a local metalworker should be able to weld something up for you that'll do the job.