There is no such thing a speaker without an amp.  You either have passive speakers, where the speaker and the amp are in separate devices, connected by speaker wire, where the speaker and amp are contained in the same device.  I don’t think anyone would recommend placing an amp in your walls, and every in ceiling/in wall speaker I’ve ever seen is passive.

Not sure what your budget is, but if you don’t have much knowledge yourself, it might be wise to hire a professional to help you make the right decisions on this.  Or perhaps look for resources to learn over the internet.  You can learn some things from a forum like this, but might miss some important details.

To answer some of your question.  Sonos products are built for multiroom audio, and you can pretty easily have speakers in various rooms in your house with minimal wiring.  The main idea here is that you will be able to play each room separately or together as you wish.  Some products are designed to be used with a TV, like the Arc, Beam, and Amp, while the others can’t be connected directly to the TV.   You could use an amp and ceiling speakers for TV audio, but you generally want the audio to come from near the TV, rather than above, so using a soundbar or amp and speakers in the wall or near would be better.  

Hi

Thank you for your reply, I understand not having everything in ceiling, however it is my preferred method, as I said my main way forward would be having minimal visible wires, though perhaps for the TV area you are right, however corridors etc i would opt for the ceiling.

I am still looking around therefore I want to see what my costs would be, my main concern is yes you are right I will need an amp however I am also not sure if i need multiple amps to control multi-room i.e say I have 4 rooms, would I need more than one amp to have such system?

Thank you

Sonos speakers are pretty good overall at not showing and wires, as you’re only going to have the power cord to deal with..   It sounds more like you’re going for the effect of having the speakers practically disappear, which is understandable.  Just noting that you can often end up reducing sound quality with that effort.

In general, I think ceiling speakers make more sense where there is not as much of target area in the room to direct sound to.  So in a bathroom, hallway, or kitchen, there is no target area, so ceiling speakers make sense.  In a living room, office, or bedroom, the majority of time you’ll be listening on the couch, desk, or bed, and you want to have speakers at ear level directed at that area.

A Sonos amp can control one zone/room only.  Meaning one audio source at one volume level. It has the speaker connections for one stereo pair of speakers.  However, with most speakers you can connect a 2nd pair of speakers to the same speaker posts without causing damage.  With the Sonance speakers Sonos sells, you can connect 3 pair.  Again though, one source at one volume.  You can also use a speaker switch to connect more speakers, but you still only have one source, and you won’t be able to control completely from the Sonos app.

So if you have a large room where you wanted two pairs of speakers, you could use a single amp.  If you had two rooms where you are ok with them always playing together at the same volume (maybe a master bedroom and on suite bathroom), then you could use a single amp.  If two rooms need to play a different source at times, then you need two amps.