From tiny Silverline's to slightly bigger PSB's

I have heard the Minuets and other PSB speakers, but not the Syncrony line. FWIW, I always find PSB speakers too forward in the upper-mids/lower treble. Also, I would not describe them as "smooth." Of course, the Syncrony might be better, and Jolida makes a nice smooth-sounding amp, so YMMV. What don't you like about the Minuet that you think the PSBs will improve?

If you are considering Johnnyb53's suggestion of a small floorstander, and since you like the Minuet's sound, the prelude would be the natural step up. Very small footprint, twice the mid/woofers, and a larger cabinet. IMHO, the Prelude offers more of what's good about the Minuet. In any case, you should focus on high-efficiancy speakers, whether monitors or floorstanders.