can strongly vouch for c63 amazing to drive sound is so addictive its actually unfair.
335 is not in the same class imo still an absolute weapon fast, refined maybe even say the interior feels a bit nicer but probably subjective. to truly compare c63 has to be m3 (speaking of which one in altona meadows going cheap 79k with fk all kms) cos v8 > 6cyl
1m is a cool little car but i wouldn't consider it in the same line as the other two options its much smaller, still fast but almost seems like a novelty car given how rare it is etc. Never been in a 1m though having said all that just a 135.
for what its worth the new 235i about to come out is a very very attractive option 0-100 4.8sec (i think it was) making it .2 slower than the M4 and 79k brand new nothing comes close for the money. Suppose you'd have to see what options you'd need on top but brand new > 4-5 year old no warranty on something like a c63.