Welcome aboard! I'll second (or third) the note about the Blackbird double layer. Definately go that route, it adds very little weight but allows you to insulate the hammock during colder nights. Because the pads are between the 2 bottom layers they don't slip around or bunch up as much and are more effective. Using a single layer bottom hammock will be harder to stay warm unless you invest in a more expensive underquilt. Being a newbie myself I just couldn't afford to buy the additional underquilt after shelling out the dough for the hammock and tarp. The CCF padding is cheap and readily available.
My only experience is the Blackbird & so far I love it, very comfortable. Don't worry about the open netting on the top, when you're covered up under a quilt or sleeping bag you'll be warm and the ventilation will prevent condensation. The shelf is nice for storing items needed during the night. Good luck and I hope you enjoy the switch to hammock camping as much as I have so far!