2 years ago a company put four wheel motors into a mini. Each weighed fifty pounds (~20kg.) and produced 150 bhp.
airfoilmod I would be interested in any link if you have one. No other interest now except curiosity.
Back to the self towing aircraft: I frankly don't think this idea would get past the first hurdle.
Does any unbiased person think that an aircraft - size say, from the 737 and bigger - could be usefully pulled by their own nosewheel? By this I mean in a day-to-day working environment, not just a flat and dry ground test.