Get the hammock, try it out. What you need will become apparent. There are all kinds of ways to do things and gadgets to help you out, but everyone finds their own balance. Make sure you have the bare minimum to hang, and see what you'd like to change. You will find dozens of options on the forums to choose from.
I do agree that a way to easily pack up the hammock and tarp is nice, but I have done fine with the sacks that came with my gear. Just got snakeskins for my hammock, but haven't used them yet.
Also make sure you have what you need to tie out the tarp: line and stakes. You probably have all that from your ground dwelling days.
When I made the change, I think all I needed at first was the hammock (came with a tarp) and a sleeping pad (which I rarely use--more trouble than it's worth to me). Upgrades happened as I used it and decided what changes would benefit me the most:
tarp tie outs
And of course I'm not done. I plan to get some doo-dads to streamline my suspension set-up, and get some kind of skins/sack for my tarp. And then when the hammock can't be improved any further, I guess it's time to start over with a new hammock.