First of all, welcome to the forum!
I got a single induction burner several years ago, originally for using outside, or elsewhere, but I ended up liking it so much, I got rid of a lot of my pans (I loved those Calphalon pots, and had them since the 70s!), and gave them to friends, who I knew could use them - the only pans on my wall now that are not induction capable are a couple of Calphalon skillets, and the copper pans. I use it, starting when I turn on my AC, and put it away when the AC goes off - I still like my gas better, but not the heat!
Amazingly, even thin pans heat fast, so a fairly cheap induction capable SS pan will work. I got a large, 4 1/2 qt, tea kettle, to replace the large one I had, and the bottom is thin, as are most tea kettles, but it will boil water faster than the high heat burners on my range, turned up just enough for the flames to come around the sides! So something this thin would be fine, for just boiling water, for stock or pasta. Of course, if you are using a pot for sautéing some onions and the like in, before adding the water and other ingredients, you might want a little thicker pan, or a disk on the bottom, like Andy has - this is not really good for gas, since the flames come up around the disk, and can burn the food on the thin area, but for induction, it's fine, and usually much cheaper than the 3 layer going all the way up the sides. I did keep my Calphalon stockpots, since I still have the option of using the gas, but if I had to move somewhere, where I had the induction, that would be my choice, for a stock pot. I have a similar, 8 qt saucepan, with a disk - I don't even know the brand name, just a commercial brand, and I use that on the range and burner for pasta
I got really good buys on Cuisinart saucepans and sauté pans, and I actually like those better than All Clads I've used in friend's kitchens - the handles feel better, and they have a slight curve on the lips, which is great for pouring (some All Clads have those now, too), and all have metal lids (I do not like glass, as I know it will eventually break!). I do have one All Clad French style pan, that I got cheap, and use frequently. I also got a deal on one MIU sauté pan, which is a good quality.
As for the CI, the bottoms of almost all are rough, and can scratch, so I sanded mine, though I rarely use them on there, anyway. Some enameled CI also have rough bottoms, while some are smooth.
On the subject of those Induction heat diffusers, I have a couple of metal disks (really all they are) I could use for that (I have them as heat diffusers over those gas flames, that don't go low enough), but I've never done it. The only pan I have that I've thought of using it for, is a large, all aluminum steamer, but I just use a wok and a bamboo steamer. Using it for all those pans I replaced would make it less efficient, for sure, and I'd have that hot metal disk, left after the cooking. But it could be used occasionally, for something like that steamer, that isn't used that often, but you wouldn't want to replace it.
Have fun with your new range, and good luck getting some deals on the pans you need.
