blast usage

@marina-manrique I'm going to start writing nispero that will run BLAST, and have some questions:

* how do you usually install BLAST on instances? (I found executables here ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/ but I'm not sure about it)

* which kind of blast I should use in metapasta? 

* where can I get metagenomics samples (I mean reads from 16S) and database?

I think that I will figure out all this things quickly if I will able to experiment with it)