What did you do with the power switch and how did you install Lion? Great job with the case btw
With the power switch, I ended up using an old switch from computer and putting it into my case, then I learned a few users on here actually make cables for this exact front panel input/output switch.(You can switch it on with the button on the front of the case) You can personally contact them, one user is BlackCH(UK-based) and the other is AlohaCab (US). They're roughly $35 and well worth saving yourself the trouble of making one yourself.
Not sure about AlohaCab's cable but make absolutely sure whether or not you have a firewire connection on your motherboard otherwise it won't work unless you ask for a jumper cable that he'll provide if you buy from BlackCH!
As far as installation, you either need a friend with a mac
A retail snowleopard Disc, it was a while back but I believe I used kakewalk to install snow leopard on a disc
then download/purchase OSX Lion and put it onto a usb drive using ###### and disk utility.. after that it was all simple kext installation(######) since my parts all pretty much worked out of the box.