Audio synthesizer with MIDI

Hello everyone,

I am doinf a application in which i need following interfaces.

1)12 channel ADC @ 10 bit(Or a multiplexer which can switch @ 500 Khz.

2)NAND Flash interface to store songs

3)Audio Codec/Decodec Library

(Or an external device like VS1053)

4)Ability to play Multiple sounds

(Do we need a extra channel on the DAC or we can do it with Soft.)

Please tell about it price is not a problem