the big difference is efficiency. efficiency is how cool your psu runs, and how much energy you use (depends if you pay for electricity if you care). hotter usually equals louder.
of the ones you have listed, i would recomend the antec (free shipping saves you like 10 bucks on a psu btw)
modular is what drives the price up. i will be the first one to say that the power supply is not something to skimp on, ever.
if modular is the most important thing, questoins.
what is your graphics card? how many hard drives, fans, disc drives etc.
http://www.newegg.com/Product/Product.a ... 6817151057
is a very good power supply, and im 98% certian the 430w will be enough. i have the non modular version of this psu powering my main rig. (and just a hint, seasonic is the oem for corsair)
if you need more juice (which i highly doubt) there is a 500w versoin thats 92 bucks
http://www.newegg.com/Product/Product.a ... 6817171035
is also a good psu.
lemme know what your running, and i'll let you know how much power you need