Rockford Fosgate 3sixty.3, maybe?
I originally used a JVC head unit, a Clarion 2/3way active crossover, and 2 amps (A mono and a 4-channel). The JVC has rear aux in, I ran an extra set of RCAs, and used that to run analog audio from my PCs headphone jack, and it worked perfectly.
WorkED only because I let the smoke out of the Clarion crossover when I accidentally hooked the ground wire to + on the battery for a second. Since the box itself was grounded to the chassis I saw lots of smoke coming from every hole, even though its upside down. Now when its hooked up properly, it outputs 12v on its remote terminal when its off (and it should never output any voltage) I haven't yet taken it apart to check out the aftermath, but needless to say its been cooked, and unhooked.
I almost ordered a direct replacement for around $100, but I ended up talking myself in to buying a Rockford Fosgate 3sixty.3 DSP instead for $400. It won't be here until Thursday, but I'm thinking it might let me pull the HU altogether.
It has 8 high level inputs (to use with a factory stereo), 8 low level, an analog aux in, an optical input, and bluetooth a2dp. It also has a wired remote with 2 knobs you can program via the USB.
I'm thinking that I'll be able to use this to get my "real volume knob" fix when i need it, and i might be able to pull the JVC head unit completely. My CarPC is a mini-pc which has optical out on the back, so I may try using that for the best quality. The optical input only accepts 48khz 24-bit (no 'HighDef', no surround).
I'm running the factory speakers in my doors still, but they were wired separately back to the trunk, so I replaced it with my 4-channel amp for the front doors, and i'm not using the rear speakers at all.
I read pretty much before I ordered it, but not as much as I've read waiting for it. You program it via USB on a Windows PC, so I was thinking how convenient it would be that I could tune it via my PC, but then I read some more and found any time the PC is connected, the remote is disabled and the onscreen remote works instead. I might have to put a switch on the USB so I can turn it on/off without actually unplugging/re-plugging.
UPS is predicting I'll have it by end of day Thursday, so I'll let you know what its like!