Quick answer. Yes, fine. Ideal choice, and you probably won't get better value, for money, without going for a real budget board, and that really is false economy. The only thing to add is that, if you want to overclock the CPU, you will need an aftermarket cooler. The one that comes with the chip is fine for stock speeds, but not for overclocking. Other than that, good to go. The only thing which might be worth considering to add, if budget allows, is an SSD (Samsung 830 128GB is ideal), which speeds up performance, amazingly.
If you think there's any possibility of you wanting to overclock, in the near future, stick with the i5-3570K and the mobo. Even if you don't want to overclock, there's little to be gained by changing. The i5-3570 is effectively the same price, and the i5-3450 is not as good. The only thing you could change, to save anything, would be to use a H77 mobo. Honestly though, unless you are certain you won't want to overclock, there's little point in "burning bridges" for the little you save.