I recently bought some Cat6 network cables from TendonUSA. They are the best network cables I have ever bought. They have this extra molding on the top that prevents the little tab from snagging on things and snapping off. Plus I really like how they look. They have this nice green connector. I know they are just cables, but I am really happy with my purchase and will definitely go back to them if I need any other types of cables.
Honestly, about 90% of the patch cords I have seen have the boot your talking about on them. But if your that happy with them great. they can be a bit of a pain when they start to harden after sitting plugged into a switch for a lengthy period of time.
Pretty much all branded, pre made patch cords have those boots on them or at the very least they have the strain relief ones.
My favorites are the flat ones, they fit really nicely in a bag all coiled up, hardly take any space at all.