The spectra of the individual LEDs is identical (for the 2700k ones) and similar (for the 4000k ones) to the spectra of the LED strip. Buy them here: https://nl.aliexpress.com/item/1005005767385166.htm
They also match the spectrum that is indicated in the datasheet at the listing.

For once, i've hit a honest vendor of 'obscure' semiconductors on Aliexpress. Most often when you buy something more 'complicated' than a BC547 or 2n3904, you get fakes.

Just a word of warning: the solder pads are on the bottom of the LEDs, so soldering these with traditional tools is not that easy. I baked two of them by using a clothes iron as a poor man's reflow system, but i couldn't get them to stay in place. I'll need to get some proper solder paste and a heat gun i guess.

It's easy enough to solder wires to the pads, but be aware they rely on the heat transfer via the big cathode pad for their cooling. Without cooling you can run them at 50mA or so (at around 7v, it has two diodes in one LED). With a 1cm² copper tab soldered to the cathode pad, it'll be completely happy at their rated 150mA current.