"Captaincapitalism":
Yes (saying so resoundingly)!!!! $18K is definitely enough money to put together a home theater system. Don't let any naysayers here tell you otherwise. Considering you can put together an entry-level home theater system for less than $2K and a highly respectable one for around $3K to about $5K, there is no reason why you cannot put together a high-end, reference caliber system for $18K if you shop around and get the best deal possible. Audiogon is one place in which you can do just that. Even with that kind of money, it is possible to get more bang for your buck. Because what you could possibly get for $18K today has probably costed about $40K to about $60K at retail a few years ago. And if you cannot put together a reference quality system for $60K, then something is wrong with you.
But anyway, if I had $18K to spend on a home theater (WHICH I DON'T), then here's the way I would do it:
Speaker System: For a complete matching speaker system, you could finish the Thiel job that you have started and go with a used pair of Thiel CS 3.6, and then match them up with a matching Thiel MCS1 to go with the Thiel Powerpoints that you already have installed inside of your ceiling. One alternative would be to seek out a used pair of Aerial Acoustics Model 10T's and then mate them to a matching Model CC3B Center Channel and keep the Thiel Powerpoints as your surrounds. Or the last alternative would be to seek out a used pair of B&W 802 Nautilus and match them up with a matching Nautilus HTM Center Channel, and still again, keep your Thiel Powerpoints as your surrounds. Price -- $4,000.00 (Fronts) + $1,000.00 (Center Channel) = $5,000.00 (all used).
Subwoofer: For a subwoofer that is consistent with the quality of the rest of the system, I would look at either a Paradigm Servo-15 or a Velodyne HGS-15. Both of these monsters will provide more than enough power and slam to shake the infrastructure of your said listening area. For the ultimate in room shaking and window rattling power, I would go for two subs if you think you can afford it. Prices -- Paradigm Servo-15 -- $1,300.00, and the Velodyne HGS-15 -- $2,200.00.
Electronics (meaning the amplification): For an $18K system, I would opt for a separate surround sound preamplifier and a separate multi-channel power amplifier. In this category, my favorite tends to be the Rotel RSP-1066 and (in your case, I would go for the most power I can buy) the matching RMB-1095 (200W x 5). But I would check out the new Parasound Halo C2 and the matching Parasound A51 (also.... 200W x 5). The price for the Rotel pair is $1,500.00 for the RSP-1066 Surround Processor and about $2,000.00 for the matching Power Amplifier. I would suspect that the new Parasound Halo pairing is identically priced.
DVD Player: If both video quality and sound quality matter to you, and you do not want to pay an arm and a leg for a reference quality player, then I would have to say that you have only one choice here. And that is the Sony DVP-NS999ES. Otherwise, I would try to seek out an used Arcam DV-88 or an used Arcam FMJ DV-27. And in the case of those Arcam players, make sure that they have the latest chips inside of them, and that they are up to the latest specs before parting with your green. Otherwise, go with a brand new Sony DVP-NS999ES. At least, you know what you're getting up front when you decide to opt for a newer Sony. The Sony DVP-NS999ES retails for about $1,200.00. But if you shop around, you should be able to get one for around $900.00 or so.
Video: For the video equation of this system, I may have to go along with the suggestion that "Tpigeon" and "Jimbo3" has made earlier. If you can, go with a fixed screen. Otherwise, a motorized one is going to cost you quite a bit more. Or, you can save yourself the trouble of calibrating a projector and a screen together altogether and get a plasma display. You should be able to get a 50" model from the likes of Panasonic, Runco, Sony (and probably, a few others) for around $6,000.00 to about $8,000.00 or so. See if you can find any closeout bargains either at any specialty video stores in your locality or somewhere on the internet.
Power Conditioning: I like "Joew's" suggestion for a Panamax M5510. But I would also take a look at Monster Cable's HTPS-7000. For a system that costs about $18K or more, you're going to need all of the protection you can get. The price for the Panamax M5510 -- $1,100.00. The Monster Cable HTPS-7000 is priced at about $1,300.00.
Cables: I don't know what kind of sound you are looking to get when it comes to cable, and since the choice of cables tend to be a subjective and personal one, I am going to leave you on your own here. But since I don't take home theater too seriously, I tend to use Monster Cable cables in my own home theater (which costs about $3K..... but will start changing some of the components in it starting late summer or early fall). I use MIT cables in my audio system (and that is separate from my home theater system).
Well...... I think that about sums it up right now. If you have any further questions, please, do not hesitate to e-mail me.
Good Luck and Happy Shopping!!!!!
I wish I had about $18K to spend on a home theater!!!!
--Charles--
P.S.: BTW........ can any of you spot me $18K so that I can buy me a state-of-the-art home theater as well (LOL)????
Just Kidding!!!!!!!