The Atria II specs:
- Sensitivity: 87.5 dB SPL/2.83 v
- Min. amplifier power: 50 watts
The OPs LAMM M 2.2 amp 18wpc
To fill the OPs room looks like higher sensitivity speakers and/or a more powerful amp. Whether the Atria+LAMM would be “loud enough” is a subjective call only the OP can answer.