I had upgraded my reading lights easily from super bright LED .com. Waited to do my florescent tubes, but these were really easy and the 18" have internal drivers. The 12" (above counter/sink) needed external drivers. Thought I'd share the link. They came from M4 products. https://m4products.com/18-f15t8/
I bought the "Natural White 4500K" for the overheads. They are slightly brighter than the originals with a similar hue.
And the "Warm White 3200K" for over the counter. They are pretty much exactly the same brightness and hue as the fluorescents.
Really like them!