No offense, but I think you're in for a bit of a shock. Have you ever even visited London? It simply does not have the same kinds of suburbs that American cities do. A 3,000 sq. ft. house in a London suburb would be considered HUGE, and would cost accordingly.

Frankly, I think you need to spend some time visiting around the London area, and accept that you are not going to find a living arrangement that is very much like what you have in a Texas suburb.

Good luck!