Managed hosting

I could use some recommendations for an exceptional managed hosting facility. We currently use Rackspace but the bandwidth allowance per server isn't cutting it anymore for some of our clients. What I'm looking for currently:

27/7 Tech support (This is very important since we don't employ any server techs)
At LEAST 1TB of bandwidth per month 2-4TB per month would be great
Working knowledge of LAMP (Linux, Apache, MySQL, and PHP) servers

Anyone have suggestions?

TechEvolution - we are actually just moving to them this weekend. We sold our hosting clients to them last year and have not heard anything negative. Most of the clients needed to always be hand-held, and TechEvolution did a great job of that