You might also consider networking with any professors at the university that are in the field you want. They can sometimes be a good source of leads. I'd also try to speak with the career services folks at the university to at least get some general direction of employers/contacts in the area that might be a good fit.
Oh, I I don't know how comfortable you are with networking, but with the informational interviews, lunches, etc... any time you are speaking with somebody, try to get two more names & contact information from each person. At the end of your conversation, ask them something like "who else would you recommend I speak to?" Get the contact info... and when you contact the new person, lead with "so & so suggested I contact you..." It will help you make that initial connection since people will open up a little more when they hear a name they're familiar/friendly with, rather than some guy (you) they've never met or heard of before.
Google "informational interviews". It is actually a technique, and there are right & wrong phrases & approaches to use. They work amazingly well. I suggested the technique to my brother-in-law who said he'd been looking and applying online for jobs for over 3 months with no luck, and few interviews. On his first 2 attempts at an informational interview (on the phone, no less), he was offered 2 jobs that weren't even posted yet.
Networking can be uncomfortable as hell, but like good running training, you've got to suck it up & put in the work. And, you'll only get out of it what you put into it.
Set a goal of building your contact list into the several hundreds. It might take that many, or you might get lucky early on. Either way, it isn't wasted effort as these new contacts are already in the area & field you're interested in, so they could prove to be valuable contacts throughout your career.