i'm only going to answer your second question.
momentary, is exactly as it says, gives power/creats a circuit for a breif moment when it is pressed.
i use 2 momentary switches for my cd drives as i have them stealthed and teh switches elsewhere on my case.
AMD athlon 64 3700
DFI lanparty ultra-d
2gb ocz ram
antec gaming case
antec 450w PSU
stock cooling and more fans
XP home sp 2
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