Speaker wattage isn't really important. Honestly any of the speakers with the 12db per octave crossover will be fine. Stay away from the 6db crossover. Some people say that your amperage per channel needs to be 1.5 - 2 times that of the speaker but really it is not a big problem. Sensitivity and impedance are the important pieces of the puzzle and the Monoprice options are solid, with 91db and 8ohms. You are probably not going to put that much power into them so don't worry about it.

For Sonos, my Understanding is you will need a soundbar to connect to the TV itself - probably the beam in your case - then you can connect any number of Sonos 1’s (or whatever they call their cheapest speaker nowadays) to that system, which would be perfect to add to a kitchen. However, this whole set up is $$$ since you need the soundbar for the TV. The individual small speakers cannot directly communicate with the TV - only the soundbar, which in turn is connected to the TV. That said, I have $$$$$ worth of Sonos in my own home and am happy with it. :)

It's true that no matter what tag database is used, the supplied information can have problems. Not usually with the big name, blockbuster mainstream albums - which for me I might cite Sgt Pepper's, Hotel California, Goodbye Yellow Brick Road and similar others - but rather the ones where the name is ambiguous, there are multiple different albums with the same name, or the album is a bit more obscure and less known. But sometimes even with well known, popular ones. There is a freeware program - contributions welcome at the downloaders option - called MP3tag. The name is misleading, it can edit and change tags for all types of sound files. MP3tag will access databases MusicBrainz and Discogs for tag info, album art, or both, at the user's choice. It's easy to use. As I said before, tag editing is essential and quite often becomes a manual rather than automatic exercise. Other than the auto ripping devices which themselves can be kludgy with sometimes undesired compromises, I know of no shortcuts. I was able to do it over a long period of time as a side effort when working on PCs. Sometimes feeding in CDs one after another while doing other things, then going back a week later to edit tags. I've always used a separate folder for each album and have them as branches off of a higher level that is by artist. For classical music, I have it organized by composer, then by artist or orchestra or conductor, then by album It's worth the effort to clean up your metadata, you'll have your music everywhere you want it and with easy and swift access to everything you have. There's another corollary programs I use to make random playlists, or genre-flavored playlists or theme playlists, for focused variety. That's a topic for another thread.

With every wireless wi-fi speaker there will need to be a power source and was about to add this fact but @anj_p beat me to it. As far as sound quality it is true wired is better than wi-fi but with the right speakers it could be hard to tell the difference. Each Wi-fi speaker will basically have a small built in receiver with a decoder and a class D power amplifier, along with the speakers and frequency crossover circuitry. All of these components in the speakers need to be top quality (and usually be of a matching brand) along with a wi-fi signal with no interference. With quality wi-fi speakers and a good wi-fi signal the difference would be negligible, but going cheap with inferior components the difference could be nearly unbearable comparable to a 2 star motel lobby or a big box store. So be prepared to pony up the cash for top quality speakers. Other reasons Music isn't reproduced to to a flawless enjoyment level is Using D class amplifiers, (and basically universal today) because they sacrifice some high fidelity for efficiency and reduced size and cheap to make, but still good little amps for most people. How you download audio files also makes a difference, when downloaded a large file it is compressed into a smaller file and some information is removed and discarded never to be reproduced again that you will never hear. Combine all of above with bad acoustics in a room and the result is a muddled mess. This is why audiophiles resort to quality class A and A/B transistor or vacuum tube power amplifiers, vinyl and CD's music sources that pump large amounts of power to big speaker systems. It's not for everyone but I would suggest going to a orchestra hall if you've haven't before and witness what real music sounds like, then decide if you want wired or wi-fi for your entertainment area and what kind of equipment to buy.