That makes sense to me, since it sounds like the underquilt is the one piece of gear you don't have in any form yet. After that, it's just a matter of upgrading for fun, but you're totally in business. Any reason you want to move away from the singlenest? I think that's a swell hammock, especially if you've swapped out the slap straps and OEM biners. Not that I would mind a Traveler either...
.. truly to enjoy bodily warmth, some small part of you must be cold, for there is no quality in this world that is not what it is merely by contrast. Nothing exists in itself. If you flatter yourself that you are all over comfortable, and have been so a long time, then you cannot be said to be comfortable any more. - Herman Melville