Host them yourself if you are using TW - get a good reliable FAST hosting company.

Just my opinion - I host with http://www.prohosters.com/ myself - I am east coast USA. I find them to be very very fast.

Kayyah servers are really slow in my experience, although I do host my cheap tours there - (tours shot with the 1-shot lens then Kayyah back office to "make" the tour)

It's funny though, on a job to job /processing time basis I make more money with the 1-shot Kayyah setup, I just hate the results - I fing the photowarp software diminshes any clarity your photo may have had in the "unwarping" process. I also dont like the gratuitous advertising for Voyager by having the "Need a Virtual Tour? Call XXX-XXX at the bottom of all my tours)

I use emax hosting.  Great support, great up time with fast servers.  I use the reseller account which in-turn gives me free hosting throughout the year.

I highly recommend them!