Using two is no problem. Find one with same or better specs- those are very high current pretty fast diodes. Don't forget that diodes that run lots of current and drop voltage, dissipate real power. These parts can drop over 2v and conduct 8A, that's 16W when conducting. I would keep the two parts close together, if you're really concerned, you could heat shrink the together so they'll track like the dual but its likely not necessary.