PJ for 3D PC-based gaming

Are you looking for 3D 1080P at 60hz per eye? Then none do it yet under $3k and not aware of any over $3k for that matter.

Can get 60hz per eye in 720P and is why most PC gamers are going with Optoma's GT750 or Acer's 5360. Both when tested for lag times against a laptop score 0 in 2D mode.

The under $3k 1080P 3D projectors are Acer H9500BD, Optoma HD33 and Epson 3010. None of whichhas been praised by a PC gamer yet. HD33 has been said to be the best compromise with PC gaming. HD33 and H9500BD have 2D input lag times around 30ms tested via laptop screen tests so actual lag times are higher. Can not say for the HD33 but the H9500BD had more input lag in 3D then in 2D mode, roughly 100-166ms in 3D. The Epson 3010 has the highest input lag, forget off hand but many gamers stay clear of it.

If you consider any posted above I highly recomend reading their official threads as none are perfect and I didn't list all Pro's/Con's of any of them.

The only projector I know with dual link DVI (because HDMI can not handle this frequency range):
http://3dvision-blog.com/6320-projec...dlp-projector/
Unfortunately too expensive.

The Acer can do 120Hz, but only at 720p. 120Hz at 1080p is out of the specifications of the HDMI interface. The frequency is simply too high. You will need dual link DVI or display port. Currently only exotic and expensive projectors provide these interfaces. Maybe the HDMI interface will be upgraded in the future and then a new generation of projectors will do the trick.

Your still gaming at 24hz which is a really bad experience.

If you want to meet you criteria (PC 1080p60 3D and sub3000$ projection), then the only current solution is dual-projectors.
I haven't been following projectors recently so I do non know the current models input lag, but since dual-projection is based on the projectors 2D modes, you should have less lag issues.
The good news is that home dual-projectors is no longer stuck with the polarized system since the availability of the Omega system, some types of projectors work better than others due to the colour spectrum approach used by Omega. See the Ultimate 3D projection thread in the >3000$ section and the Omega Optical thread in the 3D tech talk section.
The bad news is that there are still no Hdmi/DVI-DualLink/DisplayPort splitters supporting 1080p60 3D so you need to use dual-outputs. So there are restrictions on graphics cards able to run a dual-projectors with proper sync. At the moment the only card which I know it works are AMD cards with the DDD 3D drivers (Nvidia 3D Vision drivers do not support dual-projectors)