I considered a set of 18" Enkei RPF1s, but I don't think that style fits an E46 at all. Maybe NT03+M's, but not the RPF1.
In saying that, 17's have my win for the ARC8. Just the right amount of meat for tyres. Are yours Hyper Black or Anthracite, and same setup as mine? If you don't mind me asking, what tyre size are you running? It appears as though 235/40/17 (as recommended by APEX) isn't readily available in Australia. Also, are you just running BMW valve stems, or are you using the APEX ones? I know for sure the wheels don't come with them.