Here's some good news for you I ended up looking into this for my own project and I came across the ESP-WROOM-32.
I've managed to fabricate the package/footprint part on Eagle if you're using eagle then I'll happily supply it for you to use.
Below is the schematic I did for mine.
You can power it using 3.3V or via a 5V to 3.3V convertor which is the design on the right hand side.
Connect CTS to GPIO39 & RTS to GPIO38 these are your data flow control pins should you wish to tell the device that you'd like to send/receive data from the pi/esp32
Connect RXD0 to GPIO15 & TXD0 to GPIO14 this is your UART Serial which connects directly into the CM3 as there is no need for a UART to USB Convertor atleast for my project I didn't need to use it and it simplifies the build down alot. However you're welcome to use one. The chip that is used for converting to USB is CP2102-QFN-P28. I've also made a footprint/package for this on eagle as well.