Recommend Amp and Preamp with Dynaudio Confidence 50

The Gryphon 300 may be in your reach.
Lots of distributor/dealers in the USA
https://gryphon-audio.dk/distributorsdealers/

Cheers George

thelapillil
Recommend Amp Dynaudio Confidence 50

Nice speaker, that has a fairly nasty load of 2.7ohms at 80hz right where all the grunt is needed from an amp. This could be even lower if there’s -phase angle in that area also.

SpecificationsSensitivity:87dB (2.83V / 1m)IEC
Power handling:400W
Impedance:4 Ω (Minimum 2.7 Ω @ 79Hz)

At 87db, a 100w at 8ohms will usually, do but with this size room >150w@8ohm, but I suggest you look for amps that are happy at this 2.7ohm load, and that can "nearly" double their 8ohm wattage to 4ohm and again to 2ohms.
"Usually" means good linear solid state amps with bi-polar output stages, EG: Gryphon, older Krell (Agostino designed), Agostino new amps ect ect

My suggestion is the Gryphon Diablo 300 integrated if you have the funds
https://gryphon-audio.dk/shop/integrated-amplifiers/gryphon-diablo-300-integrated-amplifier/

Cheers George