I think I can give you the most detailed insight to your question. I recently built an E-350 system using the twin brother to the case you are looking at (ISK 310-150) AND I have a kill-a-watt meter hooked up to it.
My case has the 150W PSU. It draws a max of 59.1W while running Prime95 and Furmark simultaneously, which is more stressful than anything it will ever see in real use. I have the case fully loaded:
Asus E35M1-I Deluxe
1x 2.5" 5400rpm HDD
1x 2.5" SSD
1x blu-ray drive
1x TV tuner
2x sticks DDR3-1333 RAM
2x 80mm fans
Using a picoPSU will result in a bit lower wattage draw because they are so much more efficient than standard PSU's (the bundled 150W isn't even 80+ rated). The 65W bundled ISK PSU does not have a fan, but the 150W bundled ISK PSU does have a fan. I can give you some subjective ratings on PSU fan noise if you want. The bundled 80mm case fan I can't comment on... I didn't use it.
Anyway, check the link in my sig for full details on the build, including power consumption.