Looking at the 4-engined Mossie further up the thread, De Havilland's actual proposal was the DH 101. An enlarged DH 98 but not exactly the same as I found out, and powered by two Napier Sabre engines with contra-props. It was supposed to carry 8000lb internally with one 1000lb bomb under each outer wing. The idea it would carry this load at minimum of 400 mph.
Here's a couple of pics of it that I got from Tony Buttler.
The bottom pic shows it compared with the DH 98 after I had scaled the pic to 1/72.