@alaindexe
With your restated budget of $1.2k, you have a good chance of securing a nice unit. If you'd consider something like @jjss49 suggested, Metrum Acc, or others used (second hand) for less than half the cost, you could wind up with a really nice DAC that way too. If you buy it right 2nd hand and don't like it, the really good units can be easier to resale later if you want to upgrade again for some reason.
Not required, but one reason some are also suggesting a "tube" DAC is you can further fine tune the sound if you want to make it ever smoother or more laid back -or- more detailed, transparent, or more forward sounding - with the change of a low cost tube. There are several other "DAC" threads on Agon to study as well. As you are, It's worth hunting the right DAC for yourself and your particular system. A good DAC can help you to further appreciate your Sugden amp and Altec speakers even more. Good Luck.