You have an M5OD-R1 in a 2000 Ranger, aka M5R1
4.0l OHV engine
You want a self adjusting pressure plate with new clutch disc, pilot bearing and slave with throwout bearing, kit
LUK is a good brand, used them for many years, no complaints
10" is usually non-self adjusting
10-1/8th" is usually self adjusting
But that's NOT a standard
Either can be used and will bolt to the flywheel
Non-self adjusting is cheaper and will work just fine, but when first installed it might be hard to get into 1st when stopped, but just for a few weeks until new clutch disc wears down a bit
And pedal travel for engage and disengage will move up on the pedal as the clutch disc wears out until its slipping at the very top
Self adjusting moves the pressure plate over the life of the clutch disc
So engage and disengage stay at the same place in pedal travel
One is not better that the other as far as engagement or longevity