You should go with knownsrv, it is fast and managed (with fast support too), and with annual payment you can get discount too. Also, they are already up and running for a while now, i am hosting my site with them for nearly a year now with very little 24-48 hours of downtime (24-48 hours in the whole year, and the main reason for this is that they changed IP so my domain had to propogate - the server was up even faster)