"I think I would try with parallel interface ram just to ensure best performance. "
but then you'll cripple performance with
"I will try using a dedicated audio codec using the I2S interface." with its 400Kbit/sec max serial transfer speed.
why? If anything go with something that has SPI interface for 4 Mbit/sec serial transfer speed.
Yes, the quad ram would work nice. I had forgotten about that.
I was thinking something like banks of these
for a thru hole part. Its on the big side physically, but not surface mount so its easy to prototype with.