This is the correct tool. $45 from Summit, ends all the drama, taping, cutoff wheels etc. Works great for rubber line, too.
I only use Russell or Aeroquip hose ends anymore. The cheap knockoffs (house brand, amazon, generics) are made of soft alloy and will only cause you pain and suffering. I also dislike the cutter-style ends (Earl's) since they are harder to work with and not considered reusable.
Stainless braid is the way to go for most applications as it's essentially armor. I haven't found huge differences in the hose quality, even including house brand options--they seem to be acceptable if you're not pushing working pressure limits (trans cooler runs under 100psi).
I'll use the push-lok hose and fittings for light duty work like coolant and breather/vent. I don't use it for hot oil or fuel just for my preference/flavor of overkill. The fittings can be a PITA to seat fully and I'll argue are tougher to work with than braided hose and ends.
IMO, hose clamps have absolutely no place on a trans cooler line, ever, no exceptions. No barb fittings either. 3 reasons: leaks suck, trans fluid burns mightily, and sudden loss of cooler flow when the line pops off or bursts will both empty the trans and completely starve it of lube oil, basically guaranteeing immediate catastrophic failure.
You can use some inverted flare-to-6AN adapter fittings in female and male which allows plumbing straight to the radiator cooler. Make sure to route thru the aux cooler first, then thru the radiator. This relieves the radiator cooler of a bunch of heat load and also ensures the trans fluid won't run too cold.
I've also cut and flared 5/16 steel hardline and used -5 tube nut & ferrule with steel -5 to -6 AN adapters (hard to find!) for a half & half approach. Again, no hose clamps. Anyone using hose clamps on AN line is an idiot in my book.
Last and most important, make damn sure to hose out the finished line with your favorite aerosol solvent and blow out with compressed air. In addition to rubber debris, there can also be bits of stainless braid (especially if cut with abrasive). These are not fun things to run thru whatever the AN line is connected to. I have seen a brand new motor instantly trashed on startup because of this.