If it is in the shower with you then you need to be careful of the rating to make sure it is suitable. There are different ratings for the proximity to water. I'm sure someone like PigletJohn will be able to tell you more than me.
That's a fantastic (if expensive) light from John Lewis. I've just had my bathroom ceiling replastered but really wish I'd thought to get the inset halogen lights removed first. I hate them. The bulbs blow frequently and are constantly falling out of the fitting.
Or, if you choose no to use an electrician who is a member of a Competent Person Scheme, you do have the freedom to apply for Building Regulations permission yourself, and to pay the fees for inspection, test and certification.
This will probably only cost about four times as much.
As others have said, there are zones for lighting in bathrooms and you must use lights suitable to the zone. For more info see this guide from John Lewis - there's a handy diagram of the zones under the bathroom and kitchen section www.johnlewis.com/buying-guides/lighting-buying-guide
We have this light from B&Q as our main light (we also have lights in the mirror).
I have spot lights in mine with wall lights on separate switches so the lighting can be softer & more relaxing for baths. Obviously the practical advice re zoning is v important and essential to follow.
We have wall lights too - I found it difficult to find a fitting that I could put bright enough light bulbs in - which is why I got the expensive one that takes two. However, the wall lights can offset this problem. You can even get cabinets or mirrors with them already in. It takes the lighting away from the shower.