For visa and work permit, you should go to the HK immigration website. They have very detailed information on the subject. You will need a work visa to work in HK, your wife can get a dependent visa if she is not working. Check out the website:
HK$10000 is not a lot of money for a flat in Hong Kong. However, if you prefer to stay close to the border, then you can get a decent size apartment (around 600-700 sq ft) in towns along the railway line - such as Taipo, Fanling or Sheung Shui. The train ride to the border is less than 30 mins and the housing prices in those areas are much lower than the HK Island or the Kowloon town center. Choose a flat in one of the newer housing development and most of the time they have broadband access.