Not sure on the pads, a parts book will tell you. Or look up ipd/FCP/Skandix and look at what they list for 140 and 240.
Not sure ABS calipers will be easy to source.
There was a small adapter I saw years ago that banjo bolted onto the two caliper inlet fittings and had one hose connector to convert a 240 caliper to a single hose. Effectively a brass (or something) rectangular prism/block with two holes all the way through and a hole at one end with a thread. It may be worth researching.
As for the 240 caliper onto a 140 with the vented rotor, yes I have done it. There is a story here somewhere that was done for the clubs magazine, I think it is in articles. Has pictures and measurements. It was not that hard in the end, just lots of trying different options until one worked.
