NEWB: Need Help With Overhaul of My Full System (55” XBR900E)

Uhhh..

Hmm. Well, I personally wouldn't worry about calibration. It's for the very most discerning, and if you don't think you're "that guy" then it isn't really necessary. I guess it's nice for when money is no object. Fortunately, Sony TV's are some of the most accurate out of the box, so calibration is less necessary. I suggest reading up on the proper settings for the X900E though so that you can get close to that "calibrated" look. I definitely wouldn't bother with a DIY disc. Either pay someone hundreds of bucks to come calibrate your TV with special tools and know-how, in your own room where the TV will be, or read about the settings and just set the TV up the way Sony intends, or you prefer, and be happy with it. My real opinion is that I would upgrade to a newer TV before calibrating.. no need to calibrate a TV that's already "dated" as far as features go (technically).

Cables - 18 gbps is enough for most stuff. I wouldn't worry about cables until you know you're missing out. Pretty sure you'd only need new cables if you were gaming on a PC that could deliver 4K at 120fps with a high amount of color sampling. If you want to get some anyway so you can sleep better, just go to Amazon and buy their brand, or get Monoprice or Mediabridge. I like Mediabridge, personally, available at Amazon. If you want to be *sure*, buy cables that come with the official "Premium High-Speed Certified HDMI" sticker on them.

Cat 5e is fine. You'll see no difference with Cat 6.. I wouldn't bother for years. Cat 5 would be different, but Cat 5e is already gigabit capable.

TV Stand.. there are so many options.. time for some furniture shopping lol. Everyone's needs and preferences are different..

I suggest checking out the Soundbar sub-forum. Lots of good options out there these days. All of the ones you mentioned are good. I also suggest looking into the high-end LG models, and I personally like the outgoing Samsung Sound+ line.

I suggest a Sony UHD Blu-ray player. They play better with Sony sets for DV. That said, I'm not sure if the X900E has DV or not.. I don't think it does. Either way, I like the Sony X800 M2. The X700 might be better for you though if DV isn't on the table. You'd have to check with the Blu-ray player sub-forum, I can't remember all of the differences off the top of my head. The X700 is a great player though and is very reasonably priced.

Mostly @p3trol_h3ad said:
- Calibaration for you 900e would mostly be a waste if money and time. Use Cinema Pro, turn down the brightness and you will be 95% to a calibration
- You won't see any advantage from replacing your HDMI cables as 18Gbps is all your TVs HDMI ports support
- Cat5e is fine for your ethernet, even if you would see a slight advantage on your LAN with Cat6 (doubtful) it won't make your Internet connection any faster
- TV stand is purely personal taste
- I had a Sony HNNT-5 with wireless rear speakers and liked it, I'd suggest the Sony HT9ZF with rears but really any soundbar would be light years better than your TV speakers
- Your TV isn't DV capable so that isn't a concern for the 4K player, I'd suggest the Sony x800m1 (not DV capable) or X800m2 if you are worried about future compatibility. But highly recommend watching some 4K bluray disks to see what the TV is really capable of.