Do you know what size case you have? From the number of drives it has I'm guessing it's a mid-tower. If you aren't sure, does it look about the same size as other peoples computers?
This may be a determining factor in what type of psu you have to get. I'm guessing you'll be lucky and it will be a mid-tower. There aren't a lot of psu's out there for micro-atx cases. But I believe microATX boards can be used in normal cases, as is hopefully your case.
Yes, but no sprinkles. For every sprinkle i find, i shall KILL you.