Suztera :
No you can't have two GTX 750Ti anyway.
I would not run two gpu on a CX 430.
The CX 430 should run on with your build. But I wouldn't use it personally. I would suggest a XFX 550W Core edition psu. This psu will be fine for future upgrades.
XFX are quite possibly the worst PSU manufacturers out there and there GPUs also have a very short life span, there is a reason why Nvidia quit their partnership with XFX
Yes OP, the CX430 will do you fine with that build. The 750ti rarely even requires a 6pin power connector and the CX430 already has one of those 6 pin connectors with a +2 pin for more demanding GPUs. I myself own a CX430 and I am very happy with my purchase. Been using it for 2+ years now with a HD7770