The reality is, you just need to look for "Pistol Powder" not a specific brand, because you probably won't find exactly what you are looking for.
Look in your reloading manual for what you want to load. Make a list of EVERY powder they have data for.
Now go to
Hodgdon's reloading center and add any that are not in your book. Now go to
Accurate and
Alliant and do the same thing. I wouldn't bother with Vhitavori, you won't find any, and if by some miracle you do, some asshat will be trying to get $60/lb for it. There are probably others I am forgetting, but you can see where this is going.
If you want, you can put them in order of preference, but take your list to your stores that sell powder, hopefully you will find something on your list.
So basically buy online when u find it and in big quantities lol. Any particular online sources that usually carry good 9mm, .45acp and .223 powders? If I am paying hazmat fees, I want to get what I need for all 3 calibers.
The good news is that you can probably find one powder that will work for both .45 and 9mm, and there lots of options available for .223. I have even seen Varget on the shelf from time to time, which is an excellent choice.
You can also set alerts for
www.grafs.com and
www.midway.com so you get an email when they have what you want in stock.