Keep in mind that as you drop from the 220/240 to 208 your amps will climb (more amps at lower volts). We have quite a few customers in our facility running these chassis (but nobody with more than 6 or 7 active blades it seems). I don't know anybody personally in Denver, but if you're looking around the country you'll find some colo providers will assist you with the shipping costs. Given the quotes you're seeing, I'd say it's possible to put you on 2 separate utility feeds for complete redundancy and still not approach half the cost you've mentioned as your "nightmare" quote. :0 Actually, we have some customers we do exactly that for.
We have all of our stuff at Red Rocks Data Center (we rent half a building from them, they have two, one very large one and one small one, we are in the small one) and have been very happy with them ever since the move from Chicago. Not sure what they would charge for your requirements. You can find contact information on their WHT profile, http://www.webhostingtalk.com/member.php?u=304968, ask for Tom, Brandon or Kris, they are excellent.
As far as facilities are concerned, the place is like a concrete bunker that is very well hidden. It was built by NASA in the 1970s? and renovated to a data center. If you want a place that is very hard to find (good for security), this is the data center. Generator + UPS backup for the whole facility plus backups for those as well. Never have had any downtime since switching with them. On a side note, it is a very interesting place because of it's history beginning with NASA. Definitely highly recommended.
Handy Networks is also nice, we toured their facility before the move from Chicago but the match just wasn't right. They are in the Qwest building off 16th and California.
Comfluent is also a great facility, they are located at mile zero, lots and lots of internet providers to choose from. Ask for Alf.
I would recommend touring all the facilities mentioned above. Not all matches are the same so you may want to investigate just for yourself.
@lockbull: Data393 is now Latisys. (Never toured their facility)