I'm looking into security for my house also with the same idea:

1. leave my downstair wide open. ie No grill (for better look also)
2. Grill up upstairs window full height, all around.
3. Alarm system with IR motion control at the entrance of my staircase
4. Since I got a baby recently and he sleep in his own room and my MIL has her own room also. The idea of security door is out. What i want to do is install a electric roller shutter at my staircase. for normal thieves will have no idea how to open it. even if they want to try the IR motion sensor will pick them up.
5. Now i have to look into my roof....hmmm

good imagination.
downstair still have alarm. U really think there is no police in this country?