Do not use an 800 ecu for timing control. Timing is everything when making power on a motor. Small differences in the curve could make your 1000 anemic or blow it up. The 1000 engine is very sensitive to detonation compared to the 800 because of the surface area of the piston crown. Sparing many details, it is a bad idea to use any ecu that is not programmed for a 1000 motor.
Im not worried about that. I have a pcv fuel/timing control wideband lambda egt and exhaust backpressure guage. Just needed to know if the interface is the same.