Go for Rice if you can afford it.
Even if Rice postgrad education isn't really very well-regarded in the US compared to its undergrad education, the experience of attending a top American school for 2 years, is, in itself, educational. Graduating from Rice though would not assure you of a job in the US. Though it may give you a leg up as you are already there, compared to starting the whole application process for a job in America from the UK.