Please Suggest An Electronic Crossover

There is a Bryston 10B listed here within your budget!

What is your application?  Are you going to add a sub, or are you converting to an active speaker?

To expand 2 way or 3 way speakers.  

Single DAC or a DAC for each channel?
or use the DAC from the crossover?

Digital crossover convert analog to digital back to analog.
MiniDSP does have a multiple crossover board that has a built in dac or just outputs digital but would require a DAC for each crossover point

go to 11audio.com Mike Powell

So is the External for the Kappa? You want to remove the  stock XO and add your own? Take care of the dip below 1 ohm? Amp killers..

First Watt B4 1500 new, 1000-1500.00 used

https://www.firstwatt.com/b4.html

Regard