BLI "no sound" diesel decoder???

I have a pair of Alco RSD-15s on order and at first I thought they had decoders installed but no QSI sound… now I see that they’re just “DCC ready” so I’ll have to install a decoder.
Has anyone installed a decoder in one of the BLI diesels and which decoder is a “best fit” for these locomotives? I assume they have a 8 pin socket…
Thanks, Ed