Buy a used Hennessy Expedition off of ebay. Go to hammockforums.net for other info and advice. There, you will get real advice from those, unlike here, who've ACTUALLY USED modern hammocks long enough to actually figure them out. It really isn't that hard, unless you're a 'tard.
If you are over 5'10", you'll need the longer Hennessy, I forget its name. Most folks start with a pad inside the hammock. A Hennessy Expedition with the now unavailable "Segmented Pad Extender" gives a "lay" that is quite flat and rivals the comfort of any bed I've ever slept in, including the I-Comfort I'm about to move to.
The SPE mentioned above is merely a sleeve that allows you to add foam "wings" to a pad. If this sounds silly, after you wake up on a 20F night all warm except for what feels like ice cube trays against your triceps, you'll then under stand.
For top insulation, just use the bag you now own as a "quilt", just stick your feet in the foot and pull it over you. The downside of this is you really don't get the benefit of the hood and need a really warm cap/balaclava or similar. PM if you have any other questions.
In a forest, above 20F, using anything else is, IMO, missing the boat.
