2.2 Channel System Processor Suggestions

If you're going to do straight two channel you'd be better off with a high quality two channel pre-amp.  If it has at least two sets of outs you can run your mains off one set and the two subs off the other set.  Connect video directly from your movie source(s) (disc player, Roku, etc.) to your tv or projector and use the analog audio outs to the pre-amp.   

You won't have all the room correction stuff, but you probably won't miss it with only two channels, especially if you add a couple more subs.  You'll be sending the 4K signal directly to your display device instead of routing it through something else.

If you insist on having a home theater device in the mix, get a preamp with home theater bypass so you don't have the home theater processor degrading sound when you're using the system for music.

Like everyone else said, a 2-channel preamp will usually have the better sound.  If you wanted a HT pre/pro, two items come to mind:

Bryston SP3 - no room correction or EQ however

Krell Foundation

Some people have mentioned sending the sound separately to a preamp, or integrated amp, and simply connecting all video equipment straight to the tv. My next question would be, how do I send the signal from the tv to the preamp? It looks like my only two options would be RCA or Fiber Optical. Would that degrade the sound compared to using HMDI?

You don't want to send the audio from the TV to the preamp.  Connect the audio from your playback device(s) directly to your preamp.  If your bluray player has analog (RCA) outputs, connect those to the preamp and send the video to the TV through an HDMI cable.  Make sense?  Not all bluray players will have analog outs, but most higher end ones will.  My Oppo 4K player and my Roku both have RCA outs.

jimmy225 is most likely asking because, like many other TV consumers, he is using a smart TV with Netflix/Spotify apps built in.  Like big_greg stated, this is never the best way to stream audio to an HT processor or preamp.  Much better to investigate streaming media players, such as Roku, AppleTV, Amazon Fire.  Or move up to higher end streamers such as Zappiti, Zidoo, Dune.