Thanks guys. They've agreed for me to self host. They are saying the prefer clients to use their servers as they have had loads of problems with crap hosts in the past but they've made an exception because of my concerns about control.
They are not a micky mouse agency, their clients include bbc (for a microsite) and a channel 4 side project (though they don't host those).
They are a full service agency, not just seo, which I need as I am launching a brand.
Cheers!