If you're asking this kind of question, you might find it a bit challenging to successfully build a power supply with that kind of output current/power from raw components. If you are primarily aiming to learn, don't care about time and cost, and are willing to go through multiple spins of a PCB (maybe with extra-thick copper so $$) then this may not apply.
Is there a switching regulator out there that will do this
It's called a buck regulator and some can be as high as 95% power efficient. That means, with 12 volts and 14 amps on the input (a power of 168 watts), the output power could be up to 160 watts or 5 volts and 32 amps.
Bearing in mind that shopping questions are off-topic on this site, so there's no ...
Nicely done photo - I wish tehy were all that good.
That's not "missing a leg" - it has been blown apart - presumably by electrical failure.
There is a reasonable prospect that there is other damage. Datasheet here.
Look for damage on lines connecting to pins 2 (input) and 3 (output) BUT could be anywhere.
The capacitor equivalent to C2 in datasheet ...