Hi there
Whether you will be taxed on the sale of your house depends on whether this was your principal residence. If it was, then provided that you owned and occupied this property for 2 out of the last 5 years, gain of $500,000 (if filing MFJ) and $250,000 (if filing MFS) will be exempt from US taxation.
I am not qualified to advise you on the best ways of bringing the proceeds to the UK, but there are other forum members with similar experience. Perhaps they can shed some light on this .....
Helen