You do not actually need NGS for that.  Just use PCR directly from isolated bacterial colonies to amplify the full 16s gene, then standard Sanger cycle sequencing will get you all the data you need.  When starting from a mixed bacterial population, just PCR 16s, clone the amplified product(s) to separate the mix and then sequence directly from the clones.  There are well established universal bacterial PCR primers for 16s in the literature. There must be hundreds of companies that can do this for you very cost effectively and will get you full 16s sequence in as little as a few days.

Anyone with a standard setup for LifeTechnologies Sanger big dye direct (cycle) sequencing can handle that sort of specific PCR target sequencing easily.  A lot of University's with a genomics/sequencing core facility will do this as well as a contract service.

E.g. one such larger commercial company is GeneWiz - http://www.genewiz.com/public/16S_rRNA.aspx

Michael is right. The method he explained is good and descriptive. NGS technology is used for assessing the population size and total diversity if you looking for full gene sequencing then Sanger method is the only way to sequence.