External Door Security - Advice Appreciated

Hi all,

Long-time lurker, first time poster. :)

Would really appreciate some external door security related advice.

Scenario: In the process of purchasing new external timber door (for our apartment in a flat) + security locks

Our lock requirements are:
* Best security possible (of course!)

• In terms of style, I want one of these silver handles (here )

• In terms of function, if someone will still be home, I want to be able to exit the house and have the door automatically lock in some way behind me, without needing to use a key to lock it. And if no-one will be staying at home, when I leave the house of course I'm happy to use a key to lock it all properly.
  eg with our current door, if someone is staying home, before I leave I will press a button on a round knob, and then close the door behind me. And that round knob will be locked. And if no-one will be at home, I press the round knob (like the "Passage Lockset", first lock, on this page), close the door AND then lock another.. lock-thing. I think it's called a Lockwood 001. Then the door is fully locked.

• I do NOT want a lock where, if you're in the home and want to lock the door, you need to use a key to lock/unlock it from the inside. ie I'd rather a lock with an inside knob.

I've tried to do quite a bit of research, but have ended up being overwhelmed and confused by the types of locks - dead-latches, dead-locks, Lockwoods, single/double-cylinder etc. So far, from what I understand deadlocks are a better security option than others. And that, if I don't want to use a key from the inside, I need to avoid double-cylinder locks…

My questions are:
1. What type of lock may suit my requirements? eg the one I linked to above with the silver handle? (mechanical entrance lockset).
2. Is there a need to ALSO install a separate deadlock on the door? Or would something like the above cover that off? Or is it better to have a second one for better security?
3. Any other general advice you may have from your experience.
4. If I've incorrectly assumed/misunderstood something, please point it out. Keen to learn!
5. Any other links for further reading material.

Thanks so much in advance, would really appreciate it.
Cheers