Would you take job "security" or career advancement?

I am going to an interview tomorrow at a Medical Examiners office in another city. I’ll spare you the long details of how many interviews I’ve gone to in the city (Pittsburgh), and the love life reasons why I initially applied to those jobs, yada yada yada.

Basically it comes down to this. The position is at a Forensics office. My dream profession is to be a Forensic Scientist/Investigator. This position would be a one year contract position (so no benefits) with the Medical Examiner. It would be part time, with varied hours, some of which could be completed at home. The position would not actually involve doing any Forensics, but would rather be to prepare their lab for a new national standard/audit that they need to meet. HOWEVER, it would be a foot in the door in a Forensics lab, and if I did a good job its not crazy to assume I would be strongly considered should an actual Forensics position open up in the future. Thus far I have applied to probably a dozen different Forensics labs for ACTUAL Forensics jobs (over the last year and a half or so) and have landed only one of them (which I turned down for reasons we won’t get into here). Monetarily I wouldn’t make nearly as much as I do now with this job. In fact they don’t even have a rate yet, it would be negotiated. But even if I got a raise from my current pay by a couple dollars the best I could expect would be a solid 10–20 thousand less than I make now. This means I would HAVE to find a full or part time job to supplement the income (by at least 10–20K). Also I would have to go on my parents insurance, which I will no longer be eligible for in August at my 26th birthday. I would also probably have to put my student loans into deferment for 2–3 months until I could settle down all the moving costs (I paid about 15k into my student loans last year, interest and principle combined).

Currently I have two jobs. I am a SR Lab Tech doing basic quality control work in an Analytical Chem Lab. I have worked here for a year and a half, initially as a contract worker and then hired on permanently. The work is easy, in the Chemistry field, the pay and benefits are great, and the people are all very nice. It unfortunately has pretty much zero career advancement possible though, especially in Forensics. I also have a part time job tutoring an autistic boy. The pay for that job is great, the work is rewarding, and the family and co workers there are awesome. But again it has no career advancement possible, especially since its not really in my field at all. I am scraping by on a lot of my bills with my current combined income, but that is mostly thanks to my student loans. If you took them out of the picture I would be VERY well off. And the money is secure, I’m not likely to lose either of these jobs unless I choose to, and I’ll probably continue to get marginal raises as time goes by.

There are other issues that are weighing on my mind (girls, friends, moving to a new city in another state, money, etc), but I’m trying to look at this ONLY with whats best for me and my career.

I have an idea of what I am going to do, but what would YOU do? Opportunity, or security?