OK. Basically you want a smartphone so you can check your mails etc where you can get wifi?
As others have said that should be fine.
One consideration is getting the PCCW wifi plan, its about HK$28 a month and then you can use wifi with the PCCW hotspots, which seem to be quite a lot of places.
Just want to add, been on their website and they are running a two month free promotion at the moment:
http://www.pccwwifi.com/wifi_2months/eng/index.html