.ffn is a suffix used at the NCBI website to signify the DNA sequence of open reading frames, in FASTA format. I believe that the equivalent files at HMPDACC end with .cds.fsa.

.ptt is also a NCBI-specific suffix, used to designate a protein feature file. It is not widely used elsewhere and I don't see it at HMPDACC. You should probably use the .gbk files instead, which will contain feature annotations.

In general, if you don't see data you want at a website, it's either because it isn't there or because you have not found/recognised it. Don't be afraid to click on files and explore their contents.