Well, as others have suggested you should probably choose your speakers before deciding about the amp, and the preamp and/or phono stage if the amp doesn't include those functions.
Provided that the X-100A is TRULY well restored, and provided that you find speakers you are happy with that are good matches for the X-100A, I think you would be unlikely to get significantly better sonics than it would provide for anything close to $500 plus the price of the speakers.
HOWEVER, going with that amp would seriously constrain your choice of speakers. It appears that the X-100A does not provide 4 ohm output taps, just 8 ohm and 16 ohm taps. So the speakers should not have an impedance which drops below the 6 to 8 ohm area at any frequency. Also, the amp's maximum power capability is only about 17 watts per channel. So the speakers you choose would have to have fairly high efficiency, to a greater or lesser degree depending on the dynamic range of the kinds of recordings you listen to (i.e., the DIFFERENCE in volume between the loudest and the softest notes, symphonic classical music being one of the most demanding genres in that respect), and on your preferred volume levels, room size, and listening distance.
As far as the JD9 possibility is concerned, the only constraint use of that phono stage would place on an integrated amp that would be used with it is likely to be that you should avoid amps having low input impedances. The JD9 has a specified output impedance of 600 ohms. Chances are that rises to significantly higher values at deep bass frequencies, perhaps something like 2000 to 4000 ohms at 20 Hz. To assure that no deep bass rolloff would occur as a result of an impedance matching issue, it would be safest to multiply the higher of those numbers by 10 to determine the minimum preferable amplifier input impedance, meaning 40K. Lower values might work satisfactorily, but would create some uncertainty.
Good luck. Regards,
-- Al
