The soundtrack is available on iTunes and Amazon. I can't see what quality they're in but I think they both cap their music at 256 kbps. These are official sources though, so I guess they're the highest quality released.
Other than that, you could try to find a physical copy of the soundtrack or contact Rockstar Games directly.
there's nothing wrong with non 4/4 time. hell, dave brubeck was celebrated for his use of odd time signatures and this album is considered a masterpiece because of it.
My favorite Ellington is in small groups. Money Jungle has already been mentioned, but I like his sessions with Johnny Hodges even better. Both Side by Side and Back to Back are amazing.
Darius Jones- Man'ish Boy. You want to hear a man wail? This here. Reminds me a bit of the Pharaoh sometimes. So raw, yet so tender at the same time.
Mostly Other People Do the Killing- Shamokin!!!Everything from the album art to the disjointed melodies to the playful soloing seems to be a tribute to early-era Ornette Coleman. Fun record.
You're getting some nice guidance in here.
If you like a melodic style of drumming, I highly recommend the Keith Jarrett Trio recordings with Jack DeJohnette. Usually recorded very well so you can hear the interplay of the drums within the melody. Whisper Not is my personal favorite.
If you haven't been following Tierney Sutton, you have been missing the hell out. She is brilliant. Technically gifted as much as anybody singing today, swings like all get out, and plays with a band that smokes.
I highly highly recommend Unsung Heroes