Making dados on the table saw is not always "possible" because of the location you may want the dado in from an end. For example, on a tall shelving unit a dado 36" up from the bottom will require you use a miter gauge or sled for that. The rip fence "typically" won't move over 36" on a job site or smaller table saw, larger ones, no problem. Then, the next issue is that you will not need an 8" dado in the next century IF you are doing general woodworking in materials under 2" thick. Most likely your material will be 3/4" thick and your dados will be 3/8" to 1/4" deep. A 6" dado set will be fine for 99% of what you will need. I have about 6 dado sets, from 3 or 4 different wobblers to 6" and 8" even a 10" for my 12" Powermatic saw. The 8" set has been on my 12" Craftsman saw for about 10 years and it never gets raised above 3/4" .The brand is Oshlun and it's a good set for the money. I also have their 6" set which would be my recommendation for a smaller saw. A larger dado set takes forever to stop spinning and puts a considerable load on a the motor during start up because if the inertia required.
Ok, then. Making dados using a router has become a much more common and popular method with the advent of router guides and DIY versions shown all over YouTube.
Wood Whisperer has an "exact width" one, Stumpy Nubs, Wood Magazine, Wood Working Journal all have them. A search here:
Lot's of You Tubes are "sponsored" these days so beware of some brief intros.
The issue with router dados is often tear out in thin veneers and multiple passes required for the desired depth. It's just not as efficient as a table saw dado, but often easier and handier to move the light weight router than a long or wide and heavy panel to the table saw, it's a trade off?
