If your inquiry is serious, and your budget reflects that, then consider emailing sales/submitting a sales ticket to one of the following companies:
1. Voxel.net/Voxrox.com; Located in NY,
sales@voxel.net; They maintain an excellent reputation, and have many enterprise & other diverse high-end offerings. They have very extensive peering and a diverse fiber mix. I would consider submitting a sales request and allowing them to come up with solutions that best suit you.
2. WebNX has a focus on custom high-end solutions in addition to the mid-range dedicated server market. Located in San Jose (correct me if I'm wrong, it's near there regardless), they also have excellent connectivity and unlike Voxel, has prices that because of their network, make WebNX popular also with gamers in addition to more high-end (read: expensive) solutions. Dan represents them on the forums here; otherwise send an email to their sales dept.
3. Tailormadeservers.com ; represented by TMS - JoseQ if I recall, I've heard excellent things about them from friends, and seen nothing but positive reviews here on WHT. As the name suggests, a custom solution would probably be right up their alley.
4. Staminus.net; I had an excellent experience during the four months I administrated a server @ staminus.net for a customer; their basic DDOS protections is relatively thorough and covers a a wide range of attacks. For the price, I don't really think you can do any better for a DDOS protected network. Although they're not known for custom hardware (i.e. not firewall/network/ddos related, judging by my experience, if they aren't too busy they will do an excellent job setting something up for you. Matt represents them on WHT.
5. Gigeservers.com -- I suppose many on WHT that Gigeservers would be the most reasonably priced DDOS-focused host, along with Staminus.net. Gigeservers, from what I've heard, may be better suited to providing a single high end solution, but at a higher price point than maybe staminus might. But gigeservers also has top-notch DDOS mitigation and customer service, so I'd suggest emailing Gigesevers in addition to Staminus. Gigeservers is located in the midwest if I recall; they are represented on here too.