That'll be sufficient, even with overclocking. Though I don't personally like corsair for power supplies, even their upper end ones. I'd look to Antec or Rosewill at this level. Seasonic as well, but I prefer them for their lower wattage flexibility.
The thing about Corsair is the bad rep from the CX and RM series. The TX is a solid series while the HX and AX are stellar, efficient and reliable products. It's just hard to recommend them because there's a "clause" or "if" that comes with the name. So people don't recommend them. There are cheaper just as good alternatives but hey that's personal preference.
No problem. As I said in my previous post, there are cheaper alternatives. I bought my 750HX last year on Black Friday for $90. SR-71 posted two good PSUs as well. I personally like the modular designs.