Power supply question

[king244]

is a micro atx power supply same as atx power supply?
i am about to build first system but am finding not many choices for a micro atx ps.... the build will be a mztx form factor so  that is why i asking....will an atx power supply work, or should i stick to my limited choice for matx...?
here is the one im thinking of, tell me what you think please.....400 w and 21v on the +12v rail....is that decent?
i will have an intel quad core processor and appropriate mb, with one 500g hard drive 1, dvd/cd rw drive, 1 media card unit, a few usb ports and a 9300 gt gpu.....? oh yeah and 3 or 4 case fans.....

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3860496&CatId=1078

[Karnac]

Micro ATX is essentially the same form factor as standard ATX, only with smaller wattage and physical size. A standard ATX power supply would work in a Micro ATX case if the physical dimensions fit.

[jbmwx]

yeah, any PSU from a major company should work as long as it fits in your pc and you got the right number of the right kind of cable your pc requires.

Micro ATX is just a smaller sized case / motherboard situation

[king244]

ok awesome.....the only thing is how do i know what size will work if i dont have the case and ps in hand?
here is the case.....
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119193

[king244]

also, is it better to have 2 12v rails at say something like 15-18a each or 1 at 21-25a?

[Karnac]

Have a look at this......

http://compreviews.about.com/od/cases/a/PSUWattage.htm