Anyway, the best seamers in the country as of right now imo are:
Tier 1: Brent Arnel, Tim Southee, Iain O'Brien
Tier 2: Andre Adams, Michael Mason, Darryl Tuffey
Tier 3: Chris Martin, Andy McKay, Hamish Bennett, Graeme Aldridge, James Franklin, Adam Milne
Those are subject to change though. I honestly don't think there is much of a difference in the tiers at all, though there is a little bit of distance between the tiers. Bennett and McKay are tier 3 mainly because I'm undecided on them, and there's other bowlers around who could be in the above lists except I've seen none of them.
Imo we have a whole bunch of bowlers who are of a very similar quality.