My first question is whether I will have any trouble fitting these parts into the 300 case. Will the case accommodate 3 3.5" drives as well as the SSD along with SLI'd 560's? Will the Hyper 212 Plus clear the RAM and the side of the case? I'm into simple designs rather than more elaborate cases, but if I will have trouble with temperatures inside the case or clearances, would the NZXT H2 work better? Will the 750TX have enough amperage and wattage to power this, or should I go with the 850? I have had good luck with PNY brand GPU's in the past, but is there another brand I should look into? Thanks for any help you can offer.
I can’t see any problems that may come up in this system. Everything from the Intel® Core™ I5 2500K to the power supply Corsair power supply looks like they will go in well and without any problems, even the SSD is coming with a 2.5 to 3.5 conversion kit for mounting the drive in a normal hard drive slot. It looks like it is going to be a fun system. And yes you have enough power from the 750TX.
Are you saying you are going to SLI out of the gate? I would recommend buying a single, more powerful GPU with the same money. I would much rather have a 580 then 2x 560. Why? IF I decided I needed more firepower down the road I would just pick up another 580; yes a lot of money, but I wouldn't have to deal with selling two older GPUs and picking up a whole new GPU solution.