H, great explanation for the free-wheeling diodes circuit.
about the bridge...... my experience but debatable
-if the motor is 20-30-40 amps, the diodes should be at least 15 or 20 amp..... easy hookup with bridge (like you said)
- 1,2, 6 or 10 amp diodes could short out..... too small ( even though the current is of short duration)
-I saw 1 implementation where they put the '+' bridge connection to the '+' dc, but I think that those diodes are not needed and don't ever
carry any current.
- also should try to use FAST SWITCHING DIODES/BRIDGE, a little more expensive, reduces the doide turn-on-time, lowering voltage spike further.

don