It is next to impossible to find a brighter projector than the w1070 that beats its black-level and contrast.
Likewise, the w1070's input lag, motion resolution, and 3D cross-talk is about as perfect as they come..so you'll only be able to match, but not noticeably beat it there.
Its color-accuracy (even when bright) is also at quite a high level (even right out of the box), so don't expect large improvement there either.
As already mentioned, there is a whole other level of black+contrast possible at around $1800-2000 and another one past that around $3000-3500(with more trade-offs than the $1800-2000 spot)..and the Benq isn't particularly quiet or flexible for mounting.
The cheapest place for better black-levels and contrast is the ~$1600 Panasonic ae8000, but it will lose some motion resolution and suffers slower input speed.
The Sony hw40 is the next cheapest option at around $2000, while also being one of the only options that can compete with the w1070 for input lag.
The Sony is fast, quiet, clear, bright accurate and contrast-y.
The Benq still beats it by a small amount for motion-clarity, but that's something you HAVE to trade-off until 2chip in-line dlps become a consumer product.
Currently, nothing LED nor lamp-based can match DLP motion-handling, and no DLP can significantly beat the w1070's native contrast.
The Sony is a very close match for motion, lag and brightness, a modest improvement for color-accuracy, and a large improvement for blacks/contrast, noise and flexibility.
Nothing else really gets this close or better in all areas for anywhere near the price..but the hw40 is about $200 above your earlier mentioned budget.
It's also worth mentioning that no projector will significantly beat the w1070's blacks/contrast unless they're being used in a dark and fairly dark-colored room..lights hitting the screen or light-colored walls/ceiling greatly reduce black/contrast depth.
Same thing for the noise..if your room isn't quiet, the quieter projector helps nothing.