Many are using golden forms of Monterey cypress for this here. Might be possible for you if in protected area during winter, as long as porch area does not get really cold, with everything freezing up.

Common Juniper 'Compressa' comes to mind, growing slowly to 6' X 1'. May be too dense for you though.

Another option is one of the many cultivars of Pinus Parviflora. You would have to do candle pruning and very closely watch the moisture content. Eventually, these pines would outgrow a pot, though could be many years.

Whatever you decide to plant, be certain to pay attention to the media you plant in. I highly recommend a coarse mix such as Al's gritty mix (search on the container forum here). Without a coarse free draining mix, you will have problems in a couple years.

hi

INSIDE is never full sun ... especially if you have those new fangled double pain [lol] modern .. gas-inside windows ... plus the fact that west windows do not get sun all day ....

so that presumption might limit your options ...

and will they be indoors all year???? .. and if so why??? ... if they spend the summer outdoors.. then you might 'get away' with various things.. indoors.. during their dormancy period ....

also ... the media is very important.. as the pepper kid said.. as well as pot size ...

so many variables.. so little time ...

care to give us more facts to work with .... or do you just want names ...

BTW.. many of the 'indoor' xmas trees.. sold this time of year.. look like conifers.. but are actually not ... you might want to think about those also ...

good luck .. sounds interesting

ken

ps: no plant mysteriously stops growing at some magical height... its all about the annual growth rate.. and how fast it gets to the height you want.. and goes right past it ... which presumes you can successfully grow TREES indoors ....

You might consider some of the C. lawsoniana 'Elwood' cultivars so popular in box stores around this time of the year; a little buyer beware is all that's required.

As an experiment we overwintered one of the golden Monterey cypresses outside in the ground with no problem, but then the temps barely dipped to 10 degF.

Just got back from Indiana where I was impressed once again by the naturally columnar junipers growing along side the Interstate...

Thank you to all who took time to read my message.

Our unheated sunroom is actually very bright, it almost all glass (top and sides). I was planning to grow there tropicals but appeared that it will be too cold in winter and i don't want to add heating cost.
Sunroom is on the second floor, so i don't want to move down containers when trees become big.
Maybe I'll put them on landing next to sunroom if it will be too hot in summer for them (i want to have two containers with conifers).
I'll take a look at cultivars that i see in your responses.
Let me know if you know some other cultivars knowing additional details. Would be nice to have a conifer with a smell in this sunroom that can serve me a some kind of winter garden.

thanks

You're also going to have to consider humidity. Indoor plants, especially those that are not designed to be indoors like conifers, need it. Use Al's Gritty Mix for whatever conifer you decide to try. The Gritty mix, plus root pruning could keep a plant at a certain size for years/decades. Bonzai...