Thanks for all your helpful comments. I've decided not to go with any of the boutique stuff as I'm never going to be able to play through them before buying. I'm therefore going to stick with either a pair of Aguilar SL212 or Darkglass DG 212 or Markbass New York 212. Anyone got an opinion of these would be helpful. Just a note, all the videos I'm finding on Darkglass sound distorted with a lot of middle. Do they have a decent low end as well?
Out of those, I would take Aguilars...