Hello @Tanner-Metzmeier,
We do not have a heat sink recommendation for VOXL2, however you can try off-the-shelf components, just be careful not apply excessive mechanical stress to the QRV5165 SIP while mounting the heat spreader to it (or removing it later).
Is there anything in particular that is causing VOXL2 to overheat (what type of processing)? We could try to help reduce the system load, if you provide more details on what you are actually running.
Alex