Maybe the Modern Logic eQ (demo coming soon - it comes from Modern Logic Console ), it's a very musical and transparent equalizer with the same dynamics and punch as the Classic Logic eQ but with THAT super-analog sound and "E" curves
Honest answer?, any of the high end well designed linear phase eq plugins out there. That's as transparent as you're gonna get
For me Nebula is about bringing a lively organic sense of colour and saturation to the table.
Though perhaps you didn't mean transparent in a literal sense, more just a sense of retaining smoothness of sound when boosting without sounding overly coloured either. In that case I would go for AlexB Black Master EQ. One of its particular strengths is applying an eq boost to vocals, keeps it sounding lush better than any other eq I've tried so far.