craigs list posting (and/or PVA?)

we need ads posted (or PVAs?) on craigslist in multiple cities. A bit confused about the PVA projects on this site, versus ad posting projects. Do we need PVAa to post our own ads? If we go with posting, I guess you have your own PVAs, correct? Please explain in your PMB [login to view URL] difference between these, [login to view URL] you handle these two, [login to view URL] your recommendation is regarding these (PVA vs posting service) Obviously we need IP switching, multiple email accounts and all the other precautions. Also let us know if you use a software (OR manual) and pros/cons. Haven't decided which is the best way to go. Please be gentle with the bids, we run a small website. Thanks.