You’ll need Joseph Corlett to properly explain. I believe he uses straps, not clips.

My daughter has a Stellar 28" single bowl undermount stainless steel kitchen sink which is great. She’s had it about 8 years and it still looks like new.

I think she has it in a frameless 30 inch cabinet.

Try build.com. Look at blanco, kohler, elkay

We used a Houzer Eston sink https://www.homedepot.com/p/HOUZER-Houzer-Eston-24-in-Stainless-Steel-Undermount-Single-D-Bowl-Kitchen-Sink-STS-1400-1-STS-1400-1/203149025 in our 27" cabinet and have been very happy with it .

The Elkay EFRU27169RW fits in a 30” frameless base. It’s the largest sink I could find that does so.

A 30" sink undermounts into a 30" cabinet if you strap, not clip or block, your sink in place, no matter what the sink manufacturer says. Hercules Universal Sink Harness or a Sink Strap or two.

Thx, does strap work on drop-in sinks as well? If clips are used, how much space is needed for them? Im thinking if I cut the sides of the sink base cabinet (but not the cabinets to the right and the left) that'll give me another inch and a half to work with. Oh one more question - to install a drop in sink can we attach it to the counter first and then lift and lower the whole thing onto the base cabinets? I imagine this would be one of those "measure twice, cut once" scenarios! It would be a nightmare if the sink didnt line up. However to futz with clips from underneath in tiny space would be a nightmare too. Thanks all, appreciate the help!

You can look at the specs of any sink you are buying which will list the cutout size.