Nice choice

not sure on how many watts you will need I just have a 900W tagen and thats more than enough. Surpose it all depends if you plan to overclock it (hope you do my i5 is at 4.2 GHZ - theses i5 are an overclokers dream)
If you do plan to clock it it may be worth getting the faster mem (depending on your budget) but the multiplers should still enable you to get a decent overclock even with the mem you have chosen.
as for the 'Arctic Cooling Freezer 7 Pro Rev 2 CPU Cooler' got one of them for my sons 'wolfdale' (my old one) and it runs very quiet and cools well (hes running at STD - doesn't want the 4.5GHz the CPU will do!) But the HSF is a good choice ,even though it feels a bit cheap when fitting, with good case airflow it should work very well.
As for the mobo think all the P55 mobos are pretty good - think they have all sorted out the early socket problems. using a Gigabtye P55-UD5 myself not sata2 but my my mobo can handle my SSD speeds so dont really need sata2 really (yet)