You definitely need good heat sinking.
Diodes, and therefore bridge rectifiers, do not parallel well. The voltage drop falls as the temperature rises, so the hottest diode takes the largest current, which can lead to thermal runaway.
When using transistors in parallel, separate emitter resistors are fitted for each transistor. You could do something like that with the rectifiers to keep the currents even, but you would loose efficiency. It is quite complicated to work out how big the resistors need to be to prevent thermal runaway.