Whats with all of the power supplies?

I was putting together a simple list of parts i was gonna use to build a simple no-frills rig and when i get to the power supplies there are 12 different "type" categories on the newegg website(I haven't built since 2005). Which one am i looking for?
Specs so far:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130542
http://www.newegg.com/Product/Product.aspx?Item=N82E16819104005
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102080

 

A name brand PSU like Thermaltake or Antec @350W is more than enough! Check this one out.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371005

 

Since it appears that you're building a budget system, you should be fine with a 400w or 450w power supply; even a good 350w or 375w should be fine. Just be sure it has a 20/24pin main power connector for the mothreboard (also called a 20+4pin), and a 4pin 12v CPU power connector (just about every power supply made these days have these connectors). However, if you plan on upgrading the CPU and video card some day, you'll want a stronger power supply, so keep that in mind. Here's a few PSUs that should be fine with your system:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817121024
http://www.newegg.com/Product/Product.aspx?Item=N82E16817159066
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104051
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371005 (This one is the least expensive of the bunch, and probably the best of the bunch too! 80PLUS certified! I see augie mentioned it above in his reply also)
I tried to select some brands known to be solid....

I hope this helps!

 

thanks, i appreciate it.