I agree, and congrats!

However, I would caution that making financial plans with the hope and assumption that “nothing unexpected will happen”, is essentially a gold-plated invitation to Murphy that they WILL happen. Combine that with plans to start the sinking fund AFTER paying off debt, seems a recipe for setbacks that could be avoided.
I would encourage you to set up sinking funds now – ID places where you’ve had “gotcha’s” before, such as home appliance repair, car repair, medical expenses, etc, and start getting those sinking funds set up and funded. Then when the gotchas do occur, and we all know they will, it will merely be a moment of “oh, now is when I dip into that fund”, rather than “oh, heck, we were so close and now we won’t be able to put money towards the snowball.”
It might mean a slightly smaller snowball, and slightly later payoff dates. But after reading this list for two years, it’s infinitely more realistic. Or, you could set up the challenge for yourself that you’re going to preserve your awesome rate of snowball repayment, AND get those sinking funds set up, by earning more with your Ebay sales. Now that’s a goal worth some gazelle effort. Because by the time you get the snowball paid off, that Ebay income will still be clicking along and its momentum will continue even after the debts are gone. Woohoo!
I wish I could say I was speaking from a place of having all this stuff set up already, and feeling comfortable with that security blanket. Bummer, that’s not the case. We’re trying to get sinking funds set up here sooner than those Murphy moments arrive, and sometimes they drain dry our brand-spankin’ new sinking funds so that we have to start over.