Ok this is going to be rather long.

I want to buy a processor with room correction (I've just given my Onkyo 818 to a homeless charity shop) and really want to avoid a modern AVR. I've got my fronts sorted with a Naim NAP 200 connected to a NAC 202 which will allow HT bypass. I have a Meridian 555 which I'll use for the rears then hopefully get another 555 for the centre speaker (More about that later).

So my real questions are:

Is a G68 still worth the money? I can't afford a HD621 at the minute so i'd be using a Bluestream SP12AB-V2 to seperate the HDMI to coax audio then 4k to my TV.

Sooo

What would be the cheapest I could get a G68 for?
How do you set a 555 up for centre and would I be better off buying a Tag AVR32 or a modern AVR with preouts and room correction?

A long, and a bit of a ramble, but help would be appreciated.
Cheers.

Naim NAC 202, Naim NAP 200, NAPSC, Chord 2Qute, B&W CM6 s2, Mac mini Roon Server, pi3 roon transport with allo digione.