^+1, you should be ok with a 450w PSU and I wold recommend a Corsair or Seasonic. As for the motherboard, if your PSU price allows, I would say that the Asus is a much better choice to go with.
Also you may want to check out this motherboard: ASUS M4A88T-V EVO, it is newer and I belive should be the same price, they are in the US. One other note, the Asus board you listed has Nvidia chipset, the ASUS M4A88T-V EVO uses an AMD chipset.