If it was me, today, and I got to do it all over again, I might get a dedicated pre/pro + pro amps + DIY subs. Unfortunately, even with your superb budget, you still cannot afford a Denon pre/pro.
One of the few reasons, for me, to get a dedicated pre/pro is for XLR outputs that can be connected to pro amps, such as made by Crown, Crest, QSC, Yamaha, Behringer, etc. You will need at least a few of these to run a mch setup.
I really like AVRat's recommendation quite a bit, and I think it deserves consideration. I just would somewhat desire having XLR connections, just because.
I don't exactly trust myself all that much in building formidable subwoofers, but I can always pay someone to help me out.
Pay $15, IIRC, for the plans.
http://forums.audioholics.com/forums/showthread.php?t=60906
You'll have money in the pocket, while getting something much more capable than anything you will most likely look at in the commerical sub realm. The size is formidable, which may be an issue for you. But, there are many other designs out there.
Now, on one hand, I would still consider ID if I were you. Contact Mark Seaton if shipping a Submersive to you is possible, and how much. Same with Danley for their tapped horns.
However, if shipping happens to be extremely high in cost, you should most definitely give the strongest consideration to the DIY stuff.