Take a look at the New Haven Display TSTFT3.5Z and their other products, also search 3M and touch screen. Digikey lists many types, review some of the data sheets to see the various types, prices, and performance.
Also their are many Touch Screen Controllers (TSC) that can go between the touch screen and a MCU like the PIC. Some connect to the MCU via SPI while also providing the interface to the screen.
For a low resolution screen you might use the MCUs ADC inputs with a TSC.