Careers in US Tax Abroad?

My spouse is English and we are talking about moving overseas (probably London area).  I hear there is some demand for professionals with US GAAP experience, but I don't hear much about US tax overseas unless it is in the context of doing expat returns.  Would a few years of US corporate tax experience be valuable in industry positions?  I know all the Big 4 firms have US corporate tax groups in London but is Big 4 culture the same overseas?  I'm not trying to work 70 hour weeks year-round when I should be traveling Europe on city breaks instead, and we have children. I look at websites of firms that do expat taxes and they look like international H&R Block, am I way off base here?  As far as work experience, I worked at a Big 4 firm through senior (in a group that was mostly consulting rather than compliance) and I've been at a boutique firm since where I do compliance and consulting for smaller, non-SEC US corporations and high net worth individuals.  I've obviously Googled and checked Indeed and a few tax specific job search sites but almost everything that comes up is expat 1040s or Big 4.