1. Yes, the only difference between the P182 ans P182SE is the mirror finish on the outside. And the price :P
2. The important thing is that you have a correct temperature inside, if you manage to keep your CPU under load at about 50 and GPU under load at about 60 maximum, than you are perfect ... making the fans faster will make it lower but also louder.
As long as you are not gaming or using hardware intensive tasks, most of the time all 3 fans can be on low.
3. I bought the Corsair VX550 because of the low cost, any PSU will work but if you do not have a modular one or if you have one which is a little bit bigger than standart (600W+) you will need to remove the fan between the PSU and HDD's. It is not really a problem as you can easily move the fan to the front position( in front of the GPU ), it saves you to buy another one.
Surely Antec tells you to buy one of their PSU, but it is not needed.
