Which 3-way amplifier to convert speaker box into active system?

I would like to convert existing 3-way loudspeaker boxes (currently with passive crossovers) into an active system. I am looking for 3-channel amplifiers with 3-way active crossovers, all together assembled ready on one single circuit board for each loudspeaker box and ready for connection. (power AC or DC; input; 3x output to speakers; nothing else). It is sufficient if the three amplifiers for one box together produce around 70 watts @ 4 ohm. It does not have to be "high end".
I have not found anything suitable online so far, only 2.1, 5.1 amps etc., plate amps only as 2-way, perhaps I am not using the right keywords.
Can anyone give me a hint, perhaps links to corresponding offers?