I use 16 oz. Chemical Guys clear bottles. A 3-pack on Amazon is under $11. I don't see them for sale on the CG page here. They have a very nice trigger head on them that doesn't seem to clog and require a lot of maintenance the way many do. I also like the efficient shape, linear from top to bottom so there is no waste with the top part of the bottle and they are skinny enough to fit quite a few of them into a compartment on your cart or shelf.
I use a Brother label printer (not maker) which takes label blanks by the roll and prints up a custom label to whatever width roll you happen to have in the printer. The Brother QL-710W is an example of a label printer. There are other models, this is just an example.
