Netsol offers a range of SRAM, NAND FLASH and other memory. Their memory ICs have a minimum 10-year product supply guarantee, which reduces the risk of obsolescence (a common problem with ICs designed for smart phones).
A precision clock is an essential component and the NJU6385 is the best Quartz driver IC available, with virtually zero jitter (0.05ps typical).
Other parts to consider are the 1580-5173 digitally controllable mic pre, SAM5916 DREAM DSP and the uNET STANDARD AES67 audio interface.
Balanced input and output stages like the THAT1206 InGenius and THAT1606 OutSmarts will keep unwanted noise out of the digital domain, from microphone to loudspeaker.