The good thing is that the USB-C ecosystem is open and a wide variety of known, vetted OEMs have stepped up to serve it.
USB-C to Lightning cables are still expensive because Apple hasn't opened the connector up for MFi certification yet, but Monoprice will happily sell you a USB-C brick with upto 40W output for $15:
https://www.monoprice.com/product?c_id=116&cp_id=10851&cs_id...