Download Audio Manager from the Market. It allows you to adjust each volume level from one screen. It also has a widget to go with it. The paid version allows you to create profiles and skin the widget.
And if the stock alarm doesn't have those "silencing" options, GentleAlarm does.
I didn't like it at first, but it is just that "gentle" cycle thing I don't like so I turned that off and tried it again. I've been using Android for my alarm 7 days a week for 10 months, and for the last week I've been back on GentleAlarm. I have nothing negative to say about it - it has a zillion options and also a good UI. You might want to check that out.