As far as quilting goes, the type thread I use is entirely dependent on the look I am going for. I highly recommend you try and get a copy of Diane Gaudynski's book "Guide to machine quilting" She has an entire chapter devoted to thread with up close photos showing the different effects you get with different weights and plys of threads. She happens to love silk thread more than anything. Beautiful but very expensive.
I do not limit myself to brand name when it comes to quilting thread and I love buying on line, I have so many more choices and don't have to leave the house. When deciding what thread I want to use I consider the application, the density of quilting, how much do I want the quilting to show or not show then I go by weight, ply and effect I want. But sometimes I will throw all that out the window for a specific color. That said, I am a self avowed thread snob and freely admit it so there are certain threads I won't even bother with any more. But I quilt on a longarm and the speed at which these machines operate are so much faster than any DSM out there. So thread I would turn my nose up to due to lint or breakage could be perfectly fine in a DSM because the reduced speed they operate is not as hard on the thread as a LA. For example, I won't use Connecting threads cotton in my LA anymore due to the amount of lint buildup but I will happily use it in my domestic for machine applique or even machine quilting. It is a little too heavy for my taste for piecing. For that I use Aurifil in the top and Bottom Line in the bobbin. I piece on a Bernina. But I have run many threads through her with no issues.
As far as fabric is concerned, I do 90% of my fabric shopping on line too. I try to find bargains and sales of fabrics from manufacturers I know I like and trust. I usually get LQS fabric $4 to $7 per yard. Rarely will I pay more than $9. It may be last years lines but to me that is worth it. But again, I am making quilts for my pleasure, not to sell. My longarming capabilities is what I sell.