I am a mono block fan... I have my reasons but I love the visual of the two units and mental framework of two channels being separately amplified.
As for the 402... Looks impressive, maybe over powered... Not that you could have to much power, but certainly the 3800 could do with less.
I am completely amazed with my Schiit Aegir mono-blocks. I'm powering KefLS50 Meta's and have been just enamored with them and the sound.
The 3800 at 92db and 4ohm, LS50's I run are 85db and 8ohm and believe it or not the Aegir do a great job powering them in mono (I was nervous and considering the Vidar mono's). With the Aegir's I'm filling my entire 1500sq/ft workshop/garage with tons of rich and highly detailed sound (+subwoofer).
Give them a try... You could be very impressed and save a few bucks.