I am from the UK and the 2 differences I "heard of" between UK and US hosting are:
1) More expensive because you get to use every MB of space(uhh I forgot what it's called). With US hosting companies, they could suspend your account if you reach 98% of your space but for UK companies, it's 100% all the way.
2) Some US search engines may not pick up your sites if you are hosted in the UK. For one of my fansites (hosted on Dreamhost of course), it appears on google.com but not on google.co.uk...and vice versa.
Other than that, it should be alright? I have a .co.uk fansite and when people type "subject name" on US search engines, it does appear at the top because subject name + .co.uk have a common relation.
...ok I am just blabbering nonsense