I keep finding all sorts of different info online. We want to install about $1000 sq feet of strand bamboo flooring in the living spaces of our rambler with a crawl space. The subfloor is plywood. We don't need vapor barrier and don't need walking to be quiet below us as it's just a crawl space, but we would love a quiet floor all around. Also something to provide some insulation would be rad. Obviously less expensive would be preferred, but if we are spending the money and time to put in something different, it seems worth it to spend a little extra and get something better if it's worth it.
Bamboo makes for an excellent flooring. I would search lumber liquidators, 1000 sq feet or more will give you an extra discount and they have some good prices. Rather then wrestle with the process of the installation watch the video in the link below and get a feel for what is right for you.
Look into cork underlament.
You sure do need a vaper barrier of 6 mil. plastic on the ground under that house and plenty of venting if you want that floor to not fail.
For general message board help, click the tab labeled "Tools," and choose "Help" from the dropdown menu.