The Sadler Vampire was/is 100 kg something dry, 250 kg loaded and a range of 500km. How much power do you need for sensors anyway? Even with 100 kg for fuel, that's a lot of weight left for warhead and electronics. That's for a straight conversion of a COTS design. I'm sure corners can be cut for something which will only run for a few hours and never fly again.
But sure, I'll go back to my cartoons again. /s