What is the best receiver to use with the A90J? Budget up to $2k

There are no receivers I can recommend to anyone. The only thing worse than a receiver is an AVR. There is nothing worse. In all of audio. Period.

wasn’t expecting an answer like that! lol 
I’m a novice but willing to learn!

If I don’t use a receiver to hook up speakers and run video sources to the television ... what would I use instead?

I’m truly confused but would really appreciate if you wouldn’t mind expanding on those thoughts :)

Well OP the issue is 2 channel play back for most audiophilers.  Most have one or the other. 2 channel playback can fill most of the HTs world with just very little effort. It's usually the type of subs used, and a center channel. Good stereo will have a wonderful phantom center. 

A small adjustment on the subs and you're HT ready.

There is an option for playthrough too. It lets you use your AV or Stereo and "Play through" the same speakers. TWO separate preamps. One for HT one for stereo.

The third option is to get an older HT with a GOOD 2 channel playback.
Mcintosh, and Krell had a good hybrid. They are OLDER now..

4th Get the best HT you can, I can't recommend one, because I don't know anything about them.

As far as Marantz, I have some 60 year old preamps that still work fine...
I love the look. Thirty Three and the 3300..

Regards

millercarbon posts the same exact message on every single home theater thread, so you can pretty much ignore because he is on a crusade to kill anything "multi-channel". 

That being said, stand-alone 2-channel gear is mostly going to be a step above multi-channel (not to say multi-channel is bad).  However, at your level with speakers that are under $400 a pair, you're budget is not going to be in the "2-channel area".

The Marantz receivers are good in the fact that they are the only AV Receivers that use a discrete analog output stage.  That being said, they are voiced on the warm side and the high frequencies are softened and rolled-off.  If that's what you want, then Marantz is a good choice.

The other direction is likely going to be very close to the sound of your Pioneer.  Many will recommend Anthem AV Receivers.  They are extremely high quality and have excellent sound, but on some systems the highs can have a bright edge.  You can get a new MRX 540 for $1600.   Alternatively, you can get a new/used MRX 720 for under $2k.  The MRX 720 is the previous model and will not have all the newest features (such as Dolby Vision, etc.), but it will have a larger power supply than the 540 and provide better sound.