Where to spend AU$6000 max ?

I am enjoying my system - Cayin A-100T(integ amp),Sony X505ES(cdp), Perreaux TU3(FM Tuner), ProAc Response 2.5 speaker.
I have been saving to upgrade current system.
Which component is the one I should upgrade with the money I saved?
I want to spend in one component so I can upgrade another one later.
What I am thinking is to buy Accuphase CD-SACD player.
My object is very smooth sound without sacrificing tonal accuracy.
When I compare my FM sound and CD sound, I like the FM sound though it is not accurate and consistent.
Do you think I can achieve this with Accuphase CD-SACD player(DP-550)?
Before spending big bucks get good power ac power isolation and conditioning so you have an idea what your present rig can do. The refinement in sound will make choosing upgrades much easier, if not obvious.