What to get first?

[kalniel]

All very true, but running a lower wattage PSU close to its maximum rating with produce more noise (& heat), run less efficiently, and ultimately reduce its lifespan, compared to a higher-rated unit...

But we're not talking about running a PSU close to it's maximum rating, we're talking about running a PSU in it's most efficient range, which means less heat, less noise and ultimately increased lifespan, compared to running a higher-rated unit.