I have a Hammock Bliss double hammock that my girlfriend and I love to spend time in just to hang out; but I wouldn't even think of spending the entire night with her in it. You know, it's that tossing and turning that get's to you after a while.
The Clark Vertex (www.junglehammock.com) was designed for two people. It's heavy and expensive, and you already mentioned you have a HH Safari Deluxe. But if you want to pursue that idea, perhaps you can try it and then tell us about it here.