Step By Step
1. Test squeezelite on Raspberry
2. acces NAS with squeeze lite
3. Test TFT touch screen on raspeberry
4. Check correct screen skin for 2.4"
5. Check DAC with raspberry (SPI or I2C or USB link?)
6. Select audio amplifier and speaker
7. Design battery charging system according power need
8. design support for circuit and TFT screen
9. ....