I can't do everything you're asking but I'll let you know what I can and share some photos.

Pinus strobus 'Green Twist' (???2-3" per year maybe less) Bickelhaupt Arboretum Photo 2005:
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Pinus strobus 'Explosion' Bickelhaupt (American Conifer Society lists it growing at {{gwi:676778}}

American Conifer Society Link:
American Conifer Society + Conifer Database

Picea omorika 'Pendula Bruns' Bickelhaupt Arb. (Grows a foot a year):
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A 'Prized' conifer: Pinus strobus 'Coney Island'
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Pinus strobus 'Oliver Dwarf' (slow-growing dwarf???2" per year):
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Pinus strobus 'Trautmann' (Flat-topped cushion)
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Tsuga canadensis 'Betty Rose'
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Tsuga canadensis 'Gentsch Globe'
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Pinus strobus 'Uncantena'
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Pinus strobus 'Sea Urchin'
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Pinus densifloraXnigra 'Jane Kluis'
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Dax

Cindy, if you are looking specifically for pines, I'd suggest Pinus contorta 'Spaan's Dwarf' or Pinus leucodermis 'Irish Belle'. Both can be found at better area nurseries, should stay in your height range (at least for quite a few years) and both have a somewhat open habit. The 'Spaan's Dwarf' will have bit more of the quirky, windswept nature you favor -
'Irish Belle' is a more of a bell-shaped dumpling, but she's a sweetie anyway!

Thank you for the suggestions and especially the wonderful pictures! I'm not looking specifically for pines, just conifers. I am wondering, since the 2 Japanese maples I have close by are upright forms, would the varieties already suggested simply look like "more of the same"? A nursery person suggested perhaps a canadian hemlock since it has the weeping nature, to complement the maples. Any opinions on that or other suggestions? The maple cultivars I am referring to are Chishio Hime and Wilson's Pink Dwarf, if that helps. Thank you!

Maples will tend to be inverted cones, so they will not have same habit as conifers which tend to be conical. Weeping types should not be placed right next to uprights without something intermediate between, otherwise a visual tension is created. Visit a place with a good conifer line or conifer feature area, like Wells-Medina in Bellevue or Pam's place (Emery's) in Lynnwood for ideas. If you see something there you like but can't visualize how it would look with the plants you have already you could ask a clerk there for a second opinion.

For kinds being sold to garden centers over a wide area (no one place will have their entire product line at one time) see the web site of Iseli nursery.

Cindy, here's a picture of the aforementioned Pinus leuchodermis (heldreichii)'Irish Bell', also a personal favorite.
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You may also want to consider a dwarf Pinus parviflora. This is Pinus parviflora 'Negishi'. Actually its closer to intermediate growth, but it gives you an idea what a dwarf will look like after a number of years and there are many cultivars that are more dwarf that would provide a nice contast with your other green conifers.
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Dan