Brake Flaring Tool....Best to Buy???

i bought an otc bubble flair from summit. worked good. double flair set from autozone, worked good. my brother...hydraulic. works good.$$$$ but he doesnt have the patience for the manual ones.
I got an otc or something from auto zone when I redid all the lines on my 66 Sat.
Anyone know what fitting are used on a 02 Suburban?
Not sure of size, but I'll bet its metric. Was into that subject w/ a Good parts guy last week. Not the confused millennials....