apple not selling usb c 61w macbook pro adapter?

You can use the current 70 watt model instead. See: 70W USB-C Power Adapter - Apple

You could also use any larger model (e.g., 96 or 140 watt). There wouldn't be an advantage to doing that but it won't do any harm. The MacBook Pro won't draw more power than it is designed to.

It won't harm your battery in any way to use a higher wattage -- even if you were to use the 140 watt adapter. The MacBook won't draw any more power than it was designed to, regardless of the wattage of the adapter. The 60 watt adapters have been discontinued.

If you are still in doubt or concerned, see the following from the Compatibility section of 70W USB-C Power Adapter - Apple

iPhone Models

• iPhone 15 Pro
• iPhone 15 Pro Max
• iPhone 15
• iPhone 15 Plus

Mac Models

• MacBook Air (15-inch, M2, 2023)
• MacBook Air (13-inch, M2, 2022)
• MacBook Air (M1, 2020)
• MacBook Air (Retina, 13‑inch, 2020)
• MacBook Air (Retina, 13-inch, 2018 - 2019)
• MacBook Pro (13‑inch, M2, 2022)
• MacBook Pro (13-inch, M1, 2020)
• MacBook Pro (13-inch, 2020)
• MacBook Pro (13-inch, 2016 - 2019)
• MacBook Pro (14‑inch, 2023)
• MacBook Pro (14‑inch, 2021)
• MacBook Pro (16‑inch, 2023)
• MacBook (Retina, 12-inch, Early 2015 – 2017)

If you'd rather get it at OWC, here is the lik to the US site (rather than Canada):

https://eshop.macsales.com/item/Apple/MNF72LLA/