alfred, its not all about the CPU..
My 1055t is sitting in a Asus Crosshairs IV 890FX which is a High End Board.. Full Fat all sugar and no artificial sweetners..
X58 is Full Fat as well all sweet and goodness...
SKT1156 is mid range, intel chipset on a diet.
I would put a 750 on that chipset with a single GPU, probably nothing more, its Intel Budget!
I believe in spending as much on your Mobo as you do CPU, I try go with a 1-1 ratio, It has always served me well, I always have balanced systems and they are always faster than more expensive stock systems with a tweak or two!
Oh.. my 1055t does 4.5ghz on my Asus board, it would not do that on a cheap board! also in everyday use other than some benchmarks, you would not notice the speed difference between 875k and 1055t if both were at 4ghz except in handbrake, where the 1055t will finish much quicker! Games would all be smooth, web pages load, 3d scenes rendered, skype chatted, hell even a few photoshop touchups in for good measure!
But the 1055 is cheaper allowing me to have a nice lovely Asus ROG Mobo with its bells and whistles.
Well each to their own I guess, and all have different needs and choices to match, but out of your 4 choices.. I still say #4 is the best CPU looking at what it does for how much it costs!
What machine do you currently use alfred.