most b series are the same.

compression level are similar ranging from 10.1:1 to 11.1:1

having lower compression gives you more room for error.

it's possible to run turbo on higher compression, but you have much less room for error.

you make more power per lbs of boost with higher compression.

i'd stick with a b18c1 block myself. it's the best medium
if you plan to get a block for the sole purpose of rebuilding it.
get the cheapest b16a block you can find, and build it up.

got money just burning a hole in your pocket, get yourself a dart block, only 1800, you'll need everything, it's just a very bare short block.