This explanation may help, Source: https://www.renovatorstore.com.au/blog/lighting-and-power-in-your-bathroom-the-simple-rules-to-be-safe/ REQUIREMENTS Zone 0: Inside the bath or shower. Any Lighting used here must have a minimum rating of IP67 (protected against immersion in water) Zone 1: Above the bath or shower to a height of 2.25m. A minimum rating of IP44 is required Zone 2: The area stretching to 0.6m outside the bath or shower and above the bath or shower if over 2.25m. An IP rating of at least IP44 is required Outside Zone: Anywhere outside zones 0, 1 & 2. Where water jets are not to be used for cleaning purposes, the general rules of BS7671 apply In addition to the above, if there is a likelihood of water jets being used for cleaning purpose in zones 1 and 2 a fitting rated a minimum IP65 must be used. Now that this has been explained, always make sure to purchase bathroom lighting according to these standards to make sure that your bathroom is always safe. You should also have this principle applied when you purchase other electrical devices such as heated towel rails, or a guide to where you'd put sockets in your bath for razors and other devices. This may also fix the common misconception that LED lights are not rated for bathrooms. Typical LED lights have an IP rating of IP66 which is more than the needed IP rating standard that bathrooms should have. - Not to mention you'd be saving a whole lot from energy bills in the long run.

If you go for down lights you will need to leave a gap around them of 100 mm between the recessed part and insulation so the insulation doesn't catch on fire. This also creates a problem with the thermal performance of your home because heat can move freely through the ceiling where there is no insulation. It can make a big difference even if there are only a few down lights. Also, down lights are very directional (send most of their light straight down) so you need to put more in to get the same effect. You could try track lights that attach to the ceiling instead. If you want a pendant go for something cheap and easy to replace if it is damaged by toys/clothes or whatever being thrown around. Ikea have lots. FYI dimmers don;t educe the power consumption, merely reduce the intensity of the light.

Couple of things to consider..... 1. With any lights above a stainless steel sink, the reflection appears on the ceiling, I don’t like it so I installed a black sink. I added very minimal pendant lights, basically they are spotlights on a stick but they can be dimmed. Also I placed mine off centre. Saying that, spotlights can also be dimmed and sometimes, less is more. 2.Pendants in the bedroom can be quite tricky.. Example...they have to be the perfect height, width and as far as a reading light, they’re not adjustable. They cost more as they need to be installed. If you don’t like them, you need to get an electrician to change them. I originally wanted pendants but opted for lamps, happy I did as my bed couldn’t quite be centred so it would have been a mistake. Good luck, hope this helps.

I like option 1 too, if you are worried about them not being big enough, can you find something like that, but that is bigger than the 16cm? Also, you could go three, I'm posting our former kitchen reno for you, the bench length is 1600 and our pendants were probably around a similar diameter, possibly slighly bigger, and given how heavy ours were in comparison to what you have chosen I definitely think you could get away with three if you liked the look better.