While Perl has become the language du jour for bioinformatics, something of this size will benefit from using something like CouchDB or BigTable. In general, I would look at Erlang. Most bio problems are massively parallelizable and that's one of the things Erlang was specifically designed to do.
My criteria for good software:
- Does it work?
- Can someone else come in, make a change, and be reasonably certain no bugs were introduced?