So I have a handle with a 30mm hole in it. I have my option of a 28mm Finest from TGN which has a base of 27mm or a 30mm Silvertip Grade A from TGN which has a base of 29mm. Which do people think would fit better? Thanks.
The 30 mm knot. That said, it is not uncommon to need to slightly enlarge the hole once you have the knot in hand. A Dremel type tool with a drum sander is ideal. It probably won't take much. I think you will find the 28 mm knot a little sloppier fit than you think it might be.
Really, though, every knot is different, and most knots are bigger than the base disc about 3 mm to 5 mm above the disc. Until you have knot and handle in hand together, you don't know how it will turn out.