You may also want to check out The Ultimate projection system: A practical discussion thread, in the digital projectors over 3000 category. The last 10 or so pages discuss a new filter system by Omega that sounds really interesting. It's not too much and you can use a couple of cheap projectors if you want, and they don't have to be 3d ones.
And you're not limited to buying a crappy/expensive passive screen, any screen will work. You would have to have either a htpc or a couple of 3d-xl or comporable units.
It sounds like the advantages of this system include increased brightness, little to no ghosting, good colors, and cheaper glasses. All of those projectors listed above are fine choices, but I'm to picky to upgrade to any of them right now because they all have certain flaws (or kinks that still have yet to be remedied by the companies) that I can't accept - whether it's ghosting, being too dim for my 146" diagonal screen, lag, hdmi blurring issues, etc. I'm sure they all would still be awesome in most homes though.
Right now I'm using a cheapo Acer h5360 that does awesome 3d for the price. Unfortunately though, it loses too many lumens in 3d mode, and it simply can't light up my screen the way it needs to. I'm pretty sure I'm going to try the Omega system, but I haven't decided if I want to gamble on two better 1080p units or just get another 5360 for now to try with it.