Since you already own one of the classic, admired and widely recorded acoustic guitar models of all time and it's not clicking fully for you, I'd say to slow down, take your time and find (but don't force) opportunities to try things out in person. You're looking for the magic one, not just a really good one. You've already got "really good". And buying online + returning gets old very fast when you're looking for that kind of magic. There's nothing wrong with not being head over heels about your D-18. Maybe it's not the best example of one, or maybe even a great D-18 just isn't your thing. That's okay; there are a lot of classic, valuable guitars that, if they were just given to me, I'd probably hand right over to a good shop to sell on consignment. Looks like there are plenty of shops around the Asheville area. Since getting around to them is inconvenient, I recommend calling those local shops and asking a manager to keep an eye out for you for guitars that they think might be the one. You've got a healthy budget, so they should be very interested in working with you. Then hopefully a visit to the (relatively) local shop with or without your family wouldn't be impossible.