Suggestions for Modifying/Upgrading my system

My first impulse was to say your amp outclasses your speakers, especially with the music you tend to listen to, but if those speakers really do it for you then screw what I think.  I had the RLD (and have a DNA-0.5 RevA) in my system for a bit and it's not the most transparent pre in stock form.  If you're married to your speakers I'd look at an SMcAudio upgrade on your RLD or maybe a better preamp.

Maybe if you can expound a bit on what you like about your system and what you'd like to improve upon we can give you better and more specific recommendations here. 

I'd build around your McCormack / Klipsch because in my opinion the advancements LP playback have by far exceeded those of your current back end. 

Any used Well Tempered turntable would offer great stability economically and the best Benz Micro cartridge your budget would allow because of their balanced presentation and their attractive upgrade program.

If your media is mainly digital I'm ignorant and still unimpressed so I wouldn't spend a dime on it, but that's me.

Good luck with it.
 

I would try to visit as many dealers as I could and audition speakers.
Like, m-db said, I think you could do better speaker wise.
I own a pair of DNA-1 monoblocks-just upgraded by SMcAudio, as well as a RLD-1. They worked very well with Vandersteen speakers.
Though I disagree with m-db, regarding digital streaming. Using 
Spotify has made me give up my CD collection. (I grew up with turntables and vinyl and can't see why I should go back). I would suggest getting a Bluesound Node. The internal dac is pretty good, and you can always upgrade later- much better than the tablet you currently use.
Bob