Sounds like you need a co-packer. There are a number of industry associations you can check out, like The National Association for the Specialty Food Trade (NASFT) or Snack Food Association (SFA), which will have directories of contract packaging companies that can help with all or some of the needs you listed. Alternatively, you can contact the associations directly and they most likely can put you in touch with a co-packer.
http://www.specialtyfood.com/knowledge-center/nasft-recommends/http://www.snackfoodindustrymarketplace.com/listing/guide/services/consulting/page/1Also, I've never worked with Lamb's Farm, a quick google search turned them up - they're local and already work with prepared salsas. Might be worth reaching out to them for an informational call.
http://lambsfarm.org/wholesale-opportunities/I'm sure you already know this, but you'll want to be sure to get signed confidentiality agreements with any company/consultant you work with before releasing your product formula.
Best of luck.