DT 770 Pro is an excellent choice, I would stick with the 32 ohm they are the most versatile - can use on phone / tablet / pc just about any device. Yes you will need an amp for the 250 ohm and yes will sound better with HD sources like FLAC, but for general purpose use for movies / games / streaming music 32 is the best choice.
Surround has many options - Windows Sonic, most Realtek on-board sounds you can enable it, Razer surround as you mentioned even the free version is also good, even games have built-in surround with "headphone" option in the sound settings. Just don't use more than one surround at a time, if you enable more than one it will sound terrible. It does sound very good when done right, and the game / movie is properly encoded.
Personally I am using a Sound Blaster Play!3 with SBX (adjustable to your liking) with a Samson SR850 and a Zalman ZM-Mic1 as my headset.