Changing from z visa to Marriage L or residency

Hi, would be grateful for your assistance. I have been legally working in Chinsa for the last three years and am married to a Chinese passport holder and own a substantial property here in Dongguan.

as I am now over 65, my employer can no longer use my services, my Work/residence permit expires in January 2013 and I require to change my visa to enable me to live with my wife in our fully paid property. My wifes housebook is issued in Kunming, but she has a Dongguan temporary residence.

Is it just a case of presenting ourselves at the Dongguan SB offices or must it be done in Kunming ? and equally important is what length of duration can i expect to receive ?is it possible to get a five year multi entry ?.

For the record, I have no other family any where apart from my Chinese wife here in Donnguan.

Many thanks