That cooler master unit is quite crappy, it has failed multiple reviews so its definitely a no go. The OCZ unit is less powerful than the Corsair 750TXV2, but the ZS series is good and it is significantly cheaper than the Corsair. The 750TXV2 is a solid unit and well reviewed. With the OCZ being $90 before MIR, and only $65 after compared to the corsair which is $105 and $95 respectively, the OCZ would be my pick on value for the money.
The modular TX750 is actually a whole different platform and its not very modular, the only modular cables are 2 PCI-E 6+2 cables, a 4 sata connector cable, and a 4+4 CPU power cable, all the rest are still hardwired. It doesnt perform quite as well as the 750 TXV2 but costs more for 4 modular cables so i wouldnt pick it over the regular TX V2