@philart - how successful indoor growing will be depends entirely on what your indoor environment is, and what you do to modify your indoor environment. In other words, not all windowsills are the same. You need to decide whether you just want to do windowsill growing, or an under lights garden. You need to be aware of the temperature range of your home or apartment. IF you are planning on creating a light garden, you need to decide what level of light you are willing to provide. Once you know these answers, only then can you really make a list of good plants for 100% indoors bonsai.
Most windows block 35% to 75% of incoming light, so full sun indoors in a south window is at best the equivalent to part shade outdoors. If you do windowsill only, you need to stick with species that prefer a shaded environment, even if you are growing in a south window. Ficus are the most adaptable choice on most lists.
If you keep your home relatively cool, some tropicals will be off your list. If you have an elderly parent or relative living with you and the heat is on even in summer, there are some tropicals you can do that won't grow when temps are below 75 F for any length of time. Buttonwood comes to mind, it basically refuses to grow unless it is above 75 F, preferably above 80 F during the day, and not too cool at night. For us northerners, on our windowsills, buttonwood sits still, with no growth except the one or two months of the year when it is so hot we can't keep up with the air conditioning. For rapid growth, Ficus generally prefer warmth too. They will sit semi-dormant for most during the 9 or 10 months of cooler weather. Eugenia & Malpighia will grow anytime the temperatures are above 60 F. Ixora wants heat, for me it is dormant 90% of the year.
So catalog your conditions. Make note of your indoor temperature range. Summer and winter. If you run your home cool in winter, a lot of the subtropicals will be quite happy with that. Windowsills can be quite cold in winter, a fact that can be used to advantage with subtropicals. Also the cold coming off the glass can be a real problem for true tropicals.
I use a light garden. As other suggested, check out your local Hydroponics grow shop. The marijuana industry has the latest and greatest info on state of the art growing techniques. My set up is antique, I still use High Pressure Sodium Lamps, not very efficient, but quite bright. I also use T-5 fixtures that were state of the art 10 years ago, but new LED have far outstripped the efficiency of T-5. They will soon go the way of the dinosaur and the HPS and incandescent bulbs. Check out the latest in LEDs. Go to a shop, you need to see them in operation. If it is not painful to look directly at a light, it is not bright enough for an indoor light garden. Marijuana and tomatoes under lights need roughly the equivalent of 50% to 75% of direct sun. This will be bright enough to grow "full sun" bonsai. A T5 fixture 12 inches above foliage will be about 25% of full sun. So check out your hydroponics shop and look at what the latest is. I have a Bougainvillea shohin that lives 100% of its life under T5 lamps, and it blooms 2 or 3 times a year. The bougie is over 5 years in my light garden. It is possible to grow just about anything under lights if you get the intensity right and the temperature range right. I even got normal compact candles and normal needles on a Japanese black pine when brought out of cold storage in January and allowed to grow in the light garden - in the brightest spot in the light garden. But I DO NOT recommend trying to do JBP indoors 100% of the time, but part of the year can work. My JBP was a one time experiment.
Remember, you can to some degree make up for lower light intensity with longer day length. I run my lamps 18 hours a day, 365 days a year. Over 18 hours and there is data to suggest you are wasting electricity, there is data showing improved growth right up to an 18 hour day length. Majority of trees do not use day length to set flowering, with Poinsettia and Chrysanthemum species being notable exceptions. There are others, but they are relatively few.
I really do recommend Ficus as your "main tree" for indoor bonsai - it will be your most tree like species that is not fussy about light intensity, humidity and temperature. Windowsill or Light Garden, Ficus will perform. If your set up is bright, Eugenia and Malpighia are my second choices. If you house temps are relatively cool, Rhododendron simsii hybrids - the florist's azalea, (not Satsuki) are a good one to try, also gardenia.
The list
@petegreg supplied is pretty good.
Hope this helps you to plan. Remember, some tropicals like cool-ish temps and some are heat lovers (thermophiles), do your research before you buy.
