A little update:
I went for a presentation of Sony VPL HW65ES projector yesterday. It was installed in a rather small adapted HT showroom with black walls and some basic acoustic treatment: http://rzutniki.com/news/n/108/Umow-sie-na-prezentacje
(there are some pictures in the link). Some conclusions:
1. the projector gives an incredible picture. I am watching movies on Panasonic ST60 plasma TV and that picture of Sony does seem to be as good (including blacks) as my TV.
2. I thought that watching 100" picture from 9' distance might be to close, but... it is not. Actually I thought that I may sit much closer to the screen (around 6') for comfortable viewing. Hence, I can move the couch from the back wall and install the back surround speakers for 7.1.2 system :-))
3. I will built some sort of shelf for the projector (hole in the back wall and a box made of drywall protruding to the other room - there will be the access only from HT room. Fortunately the projector fans are face to the front, so there will be no problem with ventilation (by the way - there's a lot of heat coming from this projector, but it is REALLY quiet! I was sitting with my head next to it and could hear it while watching a movie with the volume turned down)
4. Still thinking about the speakers plus amplifier plus screen vs the budget...
a) if my new house turns out to be reasonably cheap and I will get some good money for the old house, I will buy probably the Denon X4400H + Dali zensor 5 or 7 (5.1 system). Was thinking about Dali Rubicon LCR (I was considering buying 3 front speakers and add some surrounds in the future) - have anyone seen these speakers? Are they worth the money spent on them?
b) in the showroom mentioned above there was a silver screen (dont remember the name or the company) which works more less the same as Magic Screen should work. There is a substantial difference in the ambient light enviroment, but when all lights were turned off, the difference was insignificant compared to standard white screen. Moreover, as the screen is silver, so is the white color (better darks, worse whites). So I think I will get some standard Adeo screen (100-105" fixed screen with dark velvet frame).