The most powerful projector that we ever shipped in DL.2 was the LX55 at 5500 lumens. There is no upgrade possible to 6000 lumens because Sanyo/Christie Digital never manufactured a projector that powerful that will fit in a DL.2.
For DL.3, we just recently started shipping the Sanyo XP200 projector which is 7000 lumens. Upgrading to this new projector is very easy, and only requires swapping projectors and making sure the DL.3 software is fully up to date.