If you just want system stats, the Vanderbilt TL10 yacht and the Lady of Shallot TL12 yacht are both detailed in the main GT sourcebook.
The TL10 ship has M1 J3; the TL12 ship has M3 J3.
In CT, the base yacht (with, I believe, no class name) was described in Book 2 and had M1 J1, but had enough fuel for three consecutive jumps.
In all cases, the ships are 200 dton, unstreamlined, have about 14 staterooms, minimal cargo, and carry a ship's boat.
I know of no "official" deckplans for any of them, though there are some from the web and there is at least one plan done in FASA's Adventure Class Ships deckplan sets.