Help please upgrading my old Pre/Pro..


IBackground:

I've been running my current system for almost 20 years and it consists of the following: It is a 5.0 system as I am not running a sub for either music/HT and I'm pretty happy with the Stratus Golds job on the bass as they go down to about 36HZ.

PSB Stratus Golds - Front Main
PSB Status C6 - Center
Niles Audio In-Walls - Rear Surround

Acurus ACT-3 Pre/Pro
Panasonic BMP-BDT 300 Blu-ray player
Aragon 8008x3 - L, R, C
Aragon 8008x2 - Rear Surrounds

Luxman 10 band Equalizer (+- 10db equalization)

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While I am very happy with this setup and it does sound great for both HT and 2 channel stereo I am looking to upgrade my PRE/PRO (Acurus). MY ACT-3 was bought in 1997 and has 24 bit Crystal DACS. It does Dolby Digital and DTS but does not have the newer decoding formats. I am also looking for a unit that will provide bass/treble adjustments as I like to boost both and is the reason I am running the Luxman in line for the Front Mains (Stratus Golds). I'd like to remove the Luxman if possible if I gain the tone controls and/or 10 band EQ in the PRE/PRO.

So my wants in a new PRE/PRO come down to this:

1) hopefully a bit better sonic quality than the Acurus ACT-3
2) new surround sound decoding that HOPEFULLY a new pre/pro can down convert to my 5.0 system? Will this sound better or just about the same as my old pre/pro processing and at that point not worthwhile to upgrade?
3) be able to adjust tone/EQ to boost the bass and treble like I prefer
4) not an absolute want but gaining wifi streaming to play music off my desktop PC and Spotify would be nice (without purchasing separate unit like SONOS connect etc. to do the streaming)

Someone mentioned to check out the new Marantz AV7703 or possibly bump up to the AV8802a but I didn't think that Marantz sound quality was on the same level with say Acurus/Aragon but I may be mistaken as I haven't listened to any of the Marantz pieces?

That said, can the "sound gurus" on this fine board provide some opinions/options on my pre/pro upgrade wishes?

venom
Maybe now is the time to try a 2.0 or 2.1 channel analog preamp using a separate HDMI switch box for video switching and using the 2.0 or 2.1 analog audio outputs from your AV sources to the preamp. That's what I do and I think it sounds much better than the 5.1 systems I've had in the past. 
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Thanks Bob. Looking for a used sub (JL, SVS etc)

What is your recommendation for implementing one sub with my Stratus Golds (Heavy Full Range 3 way floor-standing speaker 36hz to 20khz)?

Should I run my Front Mains full range and then blend the subs at about 45-50hz? Or should I high pass the fronts at about 45-50hz and set sub to about 55-60hz to blend the crossover point?