I have/had two of the very same OTC tools you listed. One worked OK for a while but gave up on stainless, and was quite hard to use with it. Gave that one away. The second set they sent as a replacement for the first, I never took the shrink wrap off it. Then I tried a nicer Imperial of similar design, also OK but nothing special, and not good for stainless either although did manage to flare a few.
The more expensive tools like the Brakequip do a mighty fine job on stainless too, almost effortless. If you can see making a couple trucks worth of lines they are well worth the money in my opinion.
I've been there and done that when it comes to brake lines, tools, and materials. Yes most anything sold for the purpose will work, I've bought and or used most all types of flare tools out there.
If you're serious about it and or enjoy working with nice tools I strongly suggest you try a Brakequip flare tool and use Copper-nickel line. (Cu-Ni line available from most auto parts stores now, even if they don't know it at first)
Grigg
