Sb/bb?

Nice sounding motors. I have a question though about SB's.... Like I said, most of my knowledge, performance wise, is in BB's, so... What would you say are the advantages and disadvantages between the 318, 340, 360? I would say one disadvantage about the 340 is the rareity, where as the 318 & 360 blocks can be obtained fairly easily, heck they were made for so long, so.... Hince why I can get a 360 motor for $125.

And to stir things up a bit, and get a wide range of opinions, what would you say are the advantages/disadvantages of SB -vs- BB? And same question but in these cars? I'm interested in hearing what everyone has to say about this, who's first? LOL.