It's a bit difficult to give much advice about placement without seeing the property or the intended areas. As a garden designer, this is exactly what I do for my business but not at all something I am comfortable with without seeing the site. There are just too many variables that need to be taken into consideration that are difficult to communicate just by discussion or even through photos.

But having said that, let me offer these thoughts to see if they can help you. 'Fjeilheim' can be planted in a tight space - it's a dwarf tree that will probably never exceed 6' tall and about half that width. The 7' deep bed will work fine. 'Koto No Ito' is best seen and admired close up, so site that where it will be very visible. It is very upright in habit (as opposed to broader and spreading) and so does not need a real wide planting area either.

'Shishigashira' also has a pretty narrow, upright habit and is a very slow grower. I have sited fairly mature ones (about 10' tall) in fairly narrow (maybe 8' wide) planting beds in an entry courtyard and they are very happy in that sort of accommodation.

The 'Viridis' and 'Golden Full Moon' will eventually develop the widest canopies of your collection if left unpruned. They will look best if allowed sufficient space to grow as they will. The full moon in particular is striking viewed at a distance, so perhaps site that away from the house where it can be viewed from indoors or from a patio. Don't worry about it getting sun - it will thrive and glow in almost complete shade with a gorgeous limey-gold color and much midday sun can scorch that golden foliage. In fact, ALL of these maples will appreciate shade during the hot parts of the day - morning sun fine; afternoon sun not so good.

HTH

Thank you gardengal-- you make some good points here, very helpful.

Glad to know the Koto No Ito won't get bigger than 6'... and that you have had good experience with the Shishigashira fairly close to the house. Right now mine is so tiny that it seems it could never get to be 25' but I suppose I need to prepare for it just in case? Some of the ones that pop up under google images are huge!

I'm not as concerned about space with the Viridis bc I can always prune that a little, and probably will anyway. But the ones that get tall make me nervous; it's not like I would want to hire someone to get up there and prune height, and I've heard that's not so good for the tree anyway? I'll keep the Golden Fullmoon in the pot for longer than the others, I imagine. Someday far far away from today when I've put a decent dent in the work right next to and around the house, I can start focusing on other areas, and find a better permanent home for him. Far far away : )

I took some pics today but it's a little embarrassing bc everything looks so yucky right now. We are in the process of getting the lawn looking better but as it was 80% weeds when we got here, it's going to take some time too. A reputable lawn service gave us an estimate for $1500/year and no, that's not in the budget for us. So I'm using this forum to walk me through some steps there too! And I couldn't get great angles for the photos bc there's huge red maple right smack in front of our front door. I love the tree but not necessarily where it's sited. Oh well.

For reference, the hydrangeas were already here and I love them so it's all good there. We are removing all the grass on the inside of the sidewalk on the left side, soon-- meant to last fall but didn't get to it. Also last fall, I planted the DeGroot's Spire, and that short little thing on the right (I lost the tag for when I bought it a few years ago--think it was a Fernspray Gold Dwarf False Cypress?), and the Green Arrow Alaskan Cedar (sunniest spot right corner there). I also have here a freshly arrived mail-order Redbud Hazel --want to site that in a way to maybe hide the gas and electric box-- and 4 more dwarf conifers on the way. Everything I bought is still tiny though so it's going to look a little silly for the next few years regardless I guess. I don't mind though.

I'll try to post progress pictures along the way. It's going to get better, little by little ; )