Is there a SoC for IoT with cellular network, Wi-Fi, Bluetooth?
Being an individual consumer not a company may limit your ability to get such chips. If you want the three technologies together: Cellular, WiFi and Bluetooth you are basically asking for a Smartphone SoC!

If you are developing for IoT, notice that you are typically designing a small product targeting low power and cost. So I don't think it makes since to have that much of wireless variety in a small IoT product with the given constraints.

To let you know, Some IoT products can rely solely on BLE, WiFi or Cellular, ANT or Zigbee or a combination of both.

Anyway, if you want some products having multiple technologies, you can check:

1- Nordic Semiconductor (Cellular) https://www.nordicsemi.com/Products/Low-power-cellular-IoT

2- Nordic Semiconductor (Bluetooth, Zigbee): https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF5340

3- Texas Instruments (WiFi): http://www.ti.com/wireless-connectivity/products.html#p367=Wi-Fi%202.4GHz

4- NXP Semiconductors (Wifi, Bluetooth): https://www.nxp.com/products/wireless/wi-fi-plus-bluetooth:WIFI-BLUETOOTH