the "new" spec pipes aren't freely available yet as such and a lot of the foreign drivers run to different rules etc so there is no hard ruling on pipes
noise isn't really an issue at the college as the nearest neighbours are a long way away
to quote LewisDXR when asked about pipes for the last meeting "as long as it doesn't sound like an ASBO'd up Subaru Impreza you should be OK"
any of the pipes from the 2007 list will be fine
as a note the BRCA are allowing 2007 spec pipes at Nationals this year anyway