Front door security recommendations pls

[mosy]

What qualities in a product to look for please for an inner front door in terms of a spyhole thingy and a chain?

Re spy/peep holes, do some give a better angle of vision? Also, the door frame is c.42mm depth, but central panel is set in so guessing maybe 2/3ds of that in mm. Can one buy "shallower" depth ones, or should I buy full depth one and "pack it with a bit of wood" on the inside to suit the dimension depth of the peephole?

On chains, no depth worries I don't think, just quality of chain to buy. The Screwfix catalogue shows some which when the door is closed also have a bolt rod as well as the sliding chain.

Any advice would be appreciated, including what one should expect to pay so rather than buying the cheapest around that could be useless.

If any recommended products, or styles of product, might be available at Sydenham DIY (I'll ask tomorrow) that would be good, but I don't know enough about what I'd be asking for yet.

Any help would much appreciated. Many thanks.

[sophie]

Definitely go to Sydenham DIY and ask them, they will give excellent advice