D400 Route or new speakers

[Womaz]

In the next couple of months I could have the cash for the next upgrade to my system.

It is listed below. I am wondering where I will get the biggest improvement either getting the Companion and going to a 400, or spending a similar amount of cash on new speakers. There is also the possibility that a Companion could be bought second hand

My room is 14ft x 23ft, and the speakers can only be a foot from the back wall.

Any opinions welcome as always