I'm actually pretty confused as to what the VDIP part actually does. In the DS_VNC1L_FW_VDIF.pdf, page 4, first paragraph it mentions something about USB port 1 being able to become the "command monitor" port, but it doesn't mention this anywhere else. Having the data sheet spread across a dozen different files with lots of replicated information is just plain strange. Needing clarification is a polite understatement...
There are a couple categories of USB devices: a standard device, a host, a hub, and some new thing they call USB "on-the-go" which is mix of a device and a host. The VDIP part is a USB Host device, and can only talk to USB devices. Your PC is also a USB Host, so your PC and the VDIP part can't talk directly to each other. There are cheap USB->RS232/serial devices which are
the easiest way of connecting a uC to a PC. So the data chain in this case (if the VDIP part could talk to a camera) would be:
Camera -> USB host chip (i.e. the VNCL1 chip) -> uC -> RF
RF -> uC -> USB device interface(*not* a VNCL1) -> computer
Although it's easier to just do
RF -> uC -> computer (through a RS232 serial port)
A UART is typically used for RS232 style data(the serial port on the PC is this type. Look it up - this is common info). PIC's should be able to use any of the interfaces, and it's up to you to decide how much bandwidth / pins you want to use.
If you use that camera module, you don't even need to use the VNCL1 parts. It isn't USB, so you don't need to bother with any of this mess. Just get a RS232 RF interface module (
https://www.radiotronix.com/ ?) and just hook it up to the computer. <waving hands furiously>