Superbrightled.com is also good. I recently read that 5050 leds are old tech and 2835s are brighter. FWIW, I gutted my 3 ceiling fluorescents and used hi density led tape with a hot-wire dimmer. The tape is, total, 5k lumens and 5k color. There's no shortage of light anymore and my old eyes need the bright white.
You might need a different fixture to get the lumens you want.
I also just bought a double sided under counter light, 4500k color and 750 lumen for $12.
I've had good luck with Amazon but led shopping is very brain damaging and it takes time to cipher different mfgrs. specs! Craig