The SONOS Connect:Amp is both a streaming device and amplifier in one.
The SONOS Play 3 and 5 are self-contained unit - Streaming, Amps, and Speakers all in one unit.
Both these units can be controlled with a Smart Device (phone, pad, tablet, etc...).
There are currently a wide range of streaming products available, some cheap, some expensive, some with amps, some without. SONOS, if you like the style, are well regarded and reasonably priced, and if my Internet connection would straighten out, I would verify that they also have Wireless Network capability.
Sonos CONNECT:AMP Wireless HiFi Player
Sonos Bridge Wireless HiFi System
Sonos Play:3 Wireless HiFi Player
Sonos Play:5 Wireless HiFi Player
Sonos Wireless Music Systems, HiFi Players, Controllers, Speakers & Accessories
If this style doesn't appeal to you, there are other brands to consider.
As to in-ceiling speakers, there are several to choose from, but you need to consider the quality you want and need. You want reasonably full range speakers.
Next, in-ceiling speakers and more importantly their wires do not magically appear in the walls and ceiling. To get the wiring in, that typically means tearing up the walls and ceiling. Not a problem if you are already remodeling, but a mess if you are not.
There are places that specialize in In-Wall/In-Ceiling speaker. Though I don't know of any specifically; I tend to run cross them randomly while searching for something else.
However. HIFIGear has a very good selection of In-Wall/In-Ceiling speakers -
Best In Ceiling Speakers | In Wall Speakers | Flat Speakers | Hifi Gear
Though many of the speaker makers like B&W, Monitor Audio, Tannoy also have In-Wall/In-Ceiling speakers, SPEAKERCRAFT is a large international manufacturer of this type of speaker, and have the longest list and widest range found at HiFiGear -
Best In Ceiling Speakers | In Wall Speakers | Flat Speakers | Hifi Gear
As a general guide rule - You get what you pay for.
Steve/bluewizard