170 degrees is perfectly fine.
To talk bacteria, you have to take into account two factors: temperature, and time. Anything between 40 and 140 is good for them, anything above 140 is bad. At the same time, food in the dangerzone that is eaten/cooked/frozen promptly, is fine, because it takes time to build up a colony of harmful proportions.
In this case your temperature is 170 degrees, which is hot enough to kill most common bacteria instantly (Milk is pasteurized in the 160s), and then you keep it at that temperature for hours? The toughest common bacteria (C. botulinum) dies very quickly at 180 degrees...It's the only one I know off the top of my head that doesn't immediately die in the 170 range. And keeping your stock at 170 for 10 minutes or so will kill any C. botulinum that may have somehow found it's way inside it.
You've got nothing to worry about.
(Basics of TDT calculation)
Formulas for stock are somewhat variable, but a common case is to use 3 kg of bones (and half a kg of mirepoix, which is a vegetable mix used for taste) with 4-5 l water, which after cooking down yields 3 l of stock, or just a little bit more than that. I couldn't find an especially good figure for the bone:meat ratio of chickens, but many Internet sites seem to agree on a 30:70 figure (I hope they didn't copy it from each other without fact checking). So, you are looking at either buying 1 pound of bones, or one 3-pound chicken per day.
In your place, I would prefer to use bones, not whole chickens, because of the logistics involved. With chickens, you'd need lots of freezer space, and then will end up with 2 lb of chicken meat daily. The work of removing the bones, especially if your recipe requires you to do so before boiling, will also cost a lot of time. But I don't know in what circumstances you live, maybe these points are not a problem for you.
If you decide to use bones, the first place to look for them would be a local meat seller. I have heard that in the US and Canada, bones are seen as a waste product and sold cheaply. If you cannot find a convenient place which sells them, you might have to ask a butchering company. They will have many bones, but are unlikely to bother to trade in small amounts, so while you are likely to get a good price, you might have to deal with a bulk delivery (and the uncooked bones will need freezing if they are to last for more than a few days).
A catering business or a restaurant might be another place to ask, as showbiz suggested, but you should be aware that fast food chains get their halfway prepared ingredients delivered from a central factory, and high-end restaurants use the bones for cooking stock for their own needs.
Best Answer
Yes, you can, if you use a pressure cooker. You can easily create stocks and bone broth in less than an hour. I prefer this method. I make all my stocks in a pressure cooker. I save a lot of time, and the flavor extraction is excellent. I ramp up the alliums, because their flavor tends to get muted in the pressure cooker. Otherwise prepare as if you were cooking your stove the traditional way. Then, cook at the highest setting for 20 minutes to an hour. Let the pressure come down naturally. Strain.