There's no such thing as getting a power supply which is too powerful is there? I mean one with a higher wattage than that recommended wont damage anything or be counter productive will it?
No, no problems with doing that (other than slightly
reduced efficiency). If you plan to CF later, it's better to go ahead and get more than you need now anyway, so you won't have to later.
If you WON'T CF later, then there's no real reason to, but it still won't hurt anything.