Will schools considered me differently as I will be new mover to HW area.
Apart from Dr Challoner Boys (as per Guest55's post, above), no, provided you are in Bucks by the date for proof of address, which we don't yet know, but I am hazarding a guess at September. It could possibly be earlier, if the deadline to apply for testing is in, say, July.
I also understand that application form , exam dates will be announce after march'13 once consultation will be over and there will be only one exam for all GS schools in Bucks area.
You are on the right track.
There is a big announcement coming up on Wednesday, and that may clarify the timeline.