T8 Fluorescent Tubes Vs T8 8ft LED Tubes

[ledmyplace]

I am having currently having T8 fluorescent tubes, all of 50W and three in number. In this regard, I have two questions.

1. How many 8ft T8 LED tubes I will need and of how many wattages to have better energy efficiency?
Also, will my costs drop or increase?
2. Also, if I am going for a complete retrofit, what else I will need besides the LED tubes?

https://www.ledmyplace.com/collections/led-tubes