Welcome to the neighborhood.
Since no one else is replying I will offer some thoughts for you to consider.
Irish music can be “dreamy” too. The whistle is an instrument. It can be used to play many types of music. Many of the folks here will have Irish or other traditional folk musics at the heart of what they play. But in the end the whistle is a tool. No matter what music you play the quality of the tone it produces is very much up up to the skill of the player - and that can take some time to develop. Keep that in mind. It’s not about the whistle.
Every whistle can be played quietly, There is a search function at the top of the page. Search for “whistle mute” and you will find some discussion on the topic. So don’t fear the volume. Susato makes narrow bore whistles, the V-series, which, while not sold as “quiet whistles”, are more tame than the S-series models which have the reputation as being particularly loud. By the way, Erik The Flutemaker is playing a Susato - his whistles are cane bodies mated to a Susato head. A Susato Oriole is a good beginner whistle IMO but louder than you might want.
Whistles like the Parks whistles have a built in volume control if you really want that type of control.
It does not really matter what whistle you choose first based on the sound examples you have provided. Buy either a Generation, Waltons (Mellow D maybe), a Feadog or an Oak. Then devote your funds to buying a stone cathedral. If one is not available in your area a smaller stone chapel may do in a pinch - marble floors and walls would help too. 
The reason I suggest this is that each of your examples are so reverb heavy that the sound of the whistle is very much buried in the recording. Your “dreamy” sound comes from the reverb and not from the whistle. Any decent whistle played well can sound like that - in the right space.
You got that one right!
Breath on a sax is nothing like breath with a whistle. You’ll be over-blowing everything if you depend on your sax chops. Fingering should come easily although you don’t have any buttons to push or flapping metal bits to cover the holes. That’s up to you and the whistle. It ain’t automatic. It will take you a bit to get things to not squeek and squawk but you’ll solve that soon enough. It’ll be fun.
Of the whistles you mention I would caution you that the Clarke and the Shaw will sound very airy and they will use a lot of air to play. So don’t go there right away. I’d think the Walton’s MD or any Dixon would be fine. The Gen or Feadog could sound a lot like the “In Dreams” recording if you can rent Notre Dame to play them in.
Actually since you really like the reverb there are a lot of places where you can achieve that. Recordings will use technology to artificially provide the depth of space you describe as “dreamy”. But natural spaces can do much the same. Stairwells are nice. Tiled bathrooms are neat too. Pedestrian tunnels in urban areas - although some of those may have other sensory artifacts that can kill the dreamy buzz. I have an all brick school a couple hundred feet from my house which provides a great natural reverb and delay if I sit at the right spot on my porch steps. Basically any space with hard reflecting surfaces can provide a nice natural reverb. It can also be fun finding those spaces. And it is not as dangerous as, say, base jumping. You don’t have to risk your life or fear being captured by the constable - usually.
I offer this clip of Sir Jimmy. He’s playing an Abell whistle - equipped with a crystal cathedral for the reverb. Hopefully you won’t hold it against him that he also plays a lot of that fast and shrill stuff too. And notice he still has a church to use for the reverb. You gotta get one!
Just buy a whistle and get started. You will find your voice in due time.
Hope that helps.
Feadoggie