Thank you much for your quick response. Looks like most of the same equipments from Premises Systems that I originally planned to use. I already purchased Lutron RadioRA, Rain8PC, Caddx 8e. For keypad/tablet, I just found out about http://www.redradio.com/
... which seems promising. Members are welcome to chime in with recomendation of hardware. Budget is always an issue, but I rather try to use the best of breed as much as possible.
Also as a software developer myself, I don't mine diving in to write additional driver/module if needed.