I almost feel sorry for the OP. By reading the first post it seems obvious that he's fed up with his flex ratchet breaking, has proposed (himself) that he might be willing to go as high up the food chain as Snap-On to have a flex ratchet with more strength.
How do we respond? 20% tell him HF is junk and move on (which he stated he already knows), 20% tell him that the HF flex ratchet is as good as the others on the market (even though he has already broke three of them), 20% chastise him for abusing his flex ratchet when h should have used a breaker bar (even though none of us know how hard it was pushed. We weren't there.) and another 20% delve into a conversation about comparative ratcheting mechanism strength (even though the OP never mentions the ratcheting mechanism).
Seems to me his question is very direct. Are there stronger brands of flex heads available?
Thank God you grace us with your presence to police the responses and ensure he solves a problem he probably doesn't have!
While I hate those test-to-fail videos, this is one of the rare places where the information has use (and it seems to correlate pretty well to the the similar videos).
Net: He's clearly using the wrong tool. Buying a more expensive tool (read: "stronger") is just going to put the edge of failure induced by using the wrong tool slightly farther out.
I'm not a professional wrench, but the guidance/advice/instruction from the wrenches I learned from often boiled down to using the right tool for the job, and using that tool correctly. Failure to do that risks damage to you, the tool, the thing you're working on, or some combination of the three.
If the ANSI spec here is a lowly 150 ft-lb (the HF Pit Pro tested to 245 in the test-to-fail vid), and he's broken three of them, do you really think buying a stronger tool that adds another 55 ft-lb to the equation is the right thing? Or should he replace the tool he already owns and get a decent breaker bar? (aka - a stronger and more proper tool for the job and likely very inexpensive)
I know it's really fun and cool these days to blame the "Chinesium" but sheesh...