Disaster Recovery - Renting Equipment

I'm putting together a disaster recovery plan and I'm trying to come up with a quick way to get new machines in place in case of catastrophic hardware failure, e.g. two servers go down at the same time (this is an HA setup and must always remain fault tolerant). At this point I'm trying to find someone who would rent a server to me, allowing me to take physical possession of it.

Why do I need physical possession of it? The problem is that I use IP-based storage on a private network and therefore can't rely on a rented server in another cabinet, even across the aisle in the same datacenter, without adding significant complexity to my setup.

So my question, in summary, is this: What would be the fastest, cheapest and simplest way to get a new server in my cabinet in a few short hours?

My servers are going to be in Colo4Dallas, so if there's a provider there who specializes in this or has made an arrangement with you or someone you know in the past, please let me know about them. If you can think of a better way to do things (the obvious solution of investing in more servers excluded),