I completely agree with wgiles check out Shug emery he has tons of how-to videos and reviews on ultralight gear and he is a pretty funny guy keeps you interested.

As for the bivy im gonna hop on the "its not a great idea" bandwagon my first sleeping bags were the military sleep system bags and they include a Goretex bivy that I mistakenly tried to use as an overnight solo set up not a good idea in colder weather though I will use it with my DD hammock tarp tent instead of a plain old Tyvek ground sheet.