Have your AR's been restored...foam surrounds and caps? You want to get the most out of them and make them easier to drive. The AR is not an efficient speaker.
The NAD is an efficient amp and puts out more power than its rated 30 wpc and may be able to drive the 10" woofers w/o any difficulty.
The Sansui 666 is from the 70s and would make for a nice vintage system. If at all possible, try and audition the Sansui with your speakers.
How large is your room?