Those Jamo are 8ohm 90dB and handle up to 120 (240) watts, so the MX3 won’t handle them well. The MX3 does 38watts into 8ohms, and I’d doubt that’s clean past 25watts. Also, the MX3 doesn’t do crossover between speakers and sub, it just feeds full signal to sub.
I’d suggest at least 100watts 8ohms into them. That’s getting into receiver or integrated amp territory. I think Yamaha has the better budget options there, but I’m more into smaller/low power Class D amps so I don’t know exactly.
The sub doesn’t have output so it can’t act as crossover. Something like the Polk PSW10 would be better.
But then I’d suggest trying the Jamo S809 by themselves before the sub. Save up for the sub.