How about using two teensy's?
This is the thing I don't understand. The command within the Arduino library Pulsin() which is almost identical to the Basic Micro version if staggered in the correct method you dont need interrupts as the command exits once the pulse is either low or high depending on what signal you feed it, so if all the device is doing is reading the pulse then your fine writing code that does not need Interrupts. The only situation where you would be wasting cpu cycles on code without the use of interrupts is if you read the channels out of order, or you start the first pulsin read when channel 1 is already finished and wait till the next pass? right?
I guess that PPM encoder Alan linked above is pretty slick little circuit, and that's an idea I had a while ago. However you could change the code to output a serial string which I think would be eaysier to parse. PPM is probably a bit lighter when attempting to interpret and requiring less pins.
They almost need a method to allow the Pwm data to be read and cached within a chip A then when chip B query's chip A it provides cached results instantaneously even though the data could be slightly out dated by (500us-2.0ms*number channels) being read. Pwm to SPI?
Not sure what does this. the receiver I have does 50hz updates I think it was..