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From all of the above I think number 2, is suitable.
Number 1 and 3 are in fact (per pictures) E3D V6 clones. They have different number of ribs on the cooled and are equiped with v6 heat block. No. 3 is probably threaded on top = prepared to be used with pneufit fiting for bowden extruder. No. 1 have also v6 throat and size of the cooler is big enough just for 30mm fan = won't fit in ToyREP as it needs cooler longer to fit under 40mm fan.
Unfortunately non of the hotends have any measurements in description, so I would suggest to ask the vendor for some measurements if possible.