One thing to remember is not all of the digital cinemas may have the (relatively new) black chip. I don't believe any are old enough to be XGA (all are SXGA right now I think), but I don't think all of them are utilizing TI's black chip which has remarkably better contrast (over 1000:1 compared...
The new LS110 with the 3.3 firmware (also comes with a bit of changed hardware) is supposed to be absolutely excellent for the price.
If you're really crazy, why not sell the house, lease the kids, and put a downpayment on a JVC QX1 priced at $220k + lens. :)
I think that Dell's new 3100MP is actually a rebadged Optoma 735, though I'm not positive. The specs aren't exactly the same (in fact, the contrast is spec'd much lower on the Dell). If it is, it's a great product for the price. If not, and Dell's quoted 280:1 on/off contrast is correct, then...
DLP theaters do vary quite a bit. Much of it has to do with the bulb choices. If you don't have a high enough wattage xenon bulb in there for the screen size, you're not going to be happy with the picture.
For HT, I think that LCOS/DILA is a very viable option in the front projector market...
This is what they use:
http://www.dlp.com/dlp/cinema/Specs.asp?mid=144
For under $5k, there are 2 great choices:
The HP XB31 XGA native DLP with 1800:1 on/off contrast, 1500 lumens.
The new Infocus LS110 with the new 3.3 firmware. The older 3.0 version wasn't as good, and there were both...