A bit of difference between the Carved top and the DC400 is the thru-neck on the DC400 and a set neck on the Carved top. But there are so many options I cannot ever keep up.. If I were to build one again I dunno? If i didnt have a neck thru I would probably do a 3 piece body neck-thru. But I would for sure have Mahogony and/or Walnut for the body option, I dunno I have not looked for a while at new Carvins.
Depending on what that DC4oo on ebay goes for could be a good deal, the clear finish is classy looking.
If it is a 2003 build it might have a similar neck as mine. Which is thin/flat. I am pretty sure i got mine in 2003. Also the bridge pickup would be a C22t standard i think. Which to my ear is Old school 1950s style treble-ly. But i have gotten used to it and find it useful. For the neck pup a C22n, again to my ear, is a nice jazzy drive-able flexible tone.