If you want the 'big' picture, you will have to get killer deals to still have the 'big' sound. Is your priority screen size or audio? You can get a great sounding audio setup w/Revel speakers, a B & K processor/pre and a number of good amps - EAD 2000 comes to mind, Outlaw if you are looking to save $ and still have some juice, and a good buy on some Sunfire or Velodynes for subs, if you run short.
BTW, please do not settle for just one sub, especially passive, trust me on this, I have five powered subs and my amps never overheat. And when there is LFE in a movie, you feel it. I would definitely get some good used connects, and
buy the speaker cable new so you can get the lengths right,
unless you measure out carefully and can find a used match.
I have had good luck with Tributary silver or silver/copper
at $5.50/ft or $ 4.00/ft respectively. There is better of course, but at least stick to something a step up from Kimber PBJ's and 4TC in your system price range. Maybe Nordost/Harmonic Tech Pro 11 or Straightwire Platinum.
Good luck!
On video, look at Fajoudia for a projector, some line quadruplers, tensioned screen and...oops. there went your
$ 25 K just on video. Maybe an 80" Pioneer Elite Pro RPT will keep you on track, unless you can scarf up some great used/demo deals.
You can have great sound, a solid front projection system,
and new components - but not all three. Not for $ 25K. My
vote is get the largest RPTV and put the rest into first class audio. Unless you find a deal or three.
If you must have the big screen, an alternative speaker setup is JMLabs( I saw one lately used for $ 3,100) w/a couple of subs(three is ideal, two 10' or 11' Sunfires in the corner and a Velodyne 15" main sub will run fast, clean tight and deep. And leave your front end to produce effortless mids and highs. I personally like extra speakers on the front/rear/sides. I am still working on the sides and extra rears, but even the front effects help out with the ambience on good DTS/DD DVD's or CD's. A progressive scan DVD is a must, Toshiba is good for the $ or you can look at
some $ 1,500 models for not much difference in picture/sound quality over the internet priced $ 600-$1,000 units.
Genesis makes great HT speakers, natch, but a little pricey
even with this budget. Of course, if you can pick up a deal,
I would grab it.