Which car for better SIP?

We have a 2001 Nissan Altima and a 2004 Toyota Sienna. DH drives the Altima to work daily, about 35 minutes each way. We really want to replace that car, primarily because it has a poor side impact rating. However, I'm also uncomfortable with the fact that our van doesn't have side air bags, either. Though I know the Sienna got a good side impact rating even without the side airbags, I would feel much more comfortable if we had them.
Money is tight right now, but I really, really want to get the Altima replaced, regardless, so we'll cut corners wherever we have to to make the payments. The question is: replace it with what? We thought about getting him a sedan with side airbags and good crash test results, but part of me thinks that perhaps we should just get a new mini-van (with side airbags, VSC, traction control, etc.) instead. Then DH could drive the old Sienna to work- not a perfect solution since it lacks side air bags, but much safer for him than the Altima. OTOH, a mini-van is overkill for a daily work commute and gas mileage runs higher than a sedan. However, I just feel like we would all be so much SAFER in a mini-van and the gas mileage would be no worse than an SUV, which millions of people commute to work in daily. If we got a new van, at least one of our cars would be what I consider to be the absolute safest vehicle currently available. The old van wouldn't be quite as safe, but still a significant improvement over the Altima. If, on the other hand, we just got DH a sedan, he'd be safer, but I would always have this nagging worry about wanting a van with side airbags and chances are, we'd end up getting another van in a few years anyway.
Also, it seems to me that prices on mini-vans have come down recently- it appears that a low-end Sienna only costs a couple grand more than a Camry. So if we can get a good deal on a mini-van, the money difference wouldn't be that significant.
Any ideas or suggestions?

FYI, the '07 Camry (with standard side curtain airbags) performed well in the IIHS side impact crash testing, earning a rating of "Good" in that test. Here's a site which compares various models in terms of their crash test results and fatality rates for each model year, assigning them a score (the lower the score the better in this scoring system): http://www.informedforlife.org/viewartcl.php?index=24 It's very helpful for comparing "apples to oranges" like you're doing, and hope it helps some in your decision making.

I can really relate to your situation because I drive a Sienna w/side curtain airbags, and DH drives an '02 Saturn L100 sedan with curtain airbags that has been crashed and repaired twice. The Saturn L-series also did not fare well in side impact crash tests even when equipped with side curtain airbags. We would like to replace the Saturn with a new Camry, budget permitting, but DH doesn't fit in the Camry. He's tall and carries most of his height in his torso, and his head is jammed up against the ceiling in the Camry. We're thinking we'll probably end up getting a Chevy Malibu Maxx for him when we can afford a different car. The Malibu Maxx also comes with standard side curtain airbags for 2007, has headroom to spare for DH even if equipped with a headroom stealing sunroof, and the Malibu has performed pretty well in side impact crash tests with optional curtain airbags in previous model years.

Good luck with your vehicle research and shopping.

Take a look at the new Hyundai minivan - it's getting rave reviews from IIHS, and comes standard with side curtain airbags for under $24k. It's supposed to get pretty good gas milage too.

The website Jean linked is a great way to compare vehicles across weight categories. Just about every model on the first couple pages ranked in risk order should be a very safe choice. Make sure whatever you buy is equipped with side curtain airbags and stability control. We now have a utility to do a quick check on specific models at our webpage www.suvsafety.info .