Bulk cable from Belkin, Comscope, USCable and a few others. Yes, almost all the cable is made in Asia. The difference is in the QC and manufacture. CAT8 is a little more difficult to handle for turns and a little more finicky to terminate correctly. Either way, if you are paying someone to install, make sure they have the equipment to verify the installation meets the frequency and signal loss specs for either. CAT6 should easily handle 10Gbit/s bandwidth for your distances and is easier to handle. CAT8 will if installed correctly. I would pull and terminate 2 cables per run since the cost is not much more.
Otherwise, just get pre-made patch cables from Belkin or other and surface mount cable panduit. Easy to replace if one goes bad or you want to upgrade.
Realistically, for home use, it’s tough to saturate 1Gbit/s .