Amp and dac decision

Ifi Neo or Topping A90 + SMSL M500 (as dac only) stack for current sennheiser hd 660s and maybe in future sennheiser hd 800s ? I like how ifi Neo have all in one combo. amp, dac, mqa… but I don’t know if Ifi Neo will be good enough to drive properly the sennheiser hd 800s. If it will, Neo gonna be my endgame unit. Or you recommend something else. DAC must have MQA for TIDAL. Can I hear diffirence in sound quality topping a90 vs topping a50s ?