I have bought my Organ brand Titanium needs from Bailey who makes the home quilting machines. I bought 100 of them and think they will last me these rest of my life. I use them for quilting and I do not change needles with every quilt. I probably do 10 or 12 quilts with one needle. Unless I have some indication that I need to change the needle, I keep on quilting with the same one, over and over again.
I use the other needles for my piecing - the kind that I just happen to have stock-piled a few years ago.
I don't seem to have issues with needles or thread, so I just keep stitching merrily along.
You can do a search on which places sell them, then get them wherever you get the best buy.
June in Cincinnati