Some time ago I looked at using VNC2 with the P1. It has 2 usb ports that can be either host (connect keyboards etc) or slave
For P2 is would be good to use one port like a FT232R, and the other port to host a HID keyboard/mouse
FTDI have a demo of how to emulate an FT232R inside the VNC2
. As a plus it claims 6Mbaud which will help with the P2.
Price of the VNC2 is about the same as the FT232R.
Against that, it needs some programming, and that's where it gets tricky