You're really not saving that much space by taking a penlight. But, what you need depends on what you're gonna be doing. If you just want to find food in the car at night, just get a penlight. If you are going to be searching for wood or setting up a tent at night, get a headlamp. The zebralight H51 is pretty cool, you can actually detach it from the straps and use it almost as thick penlight. It's all complete flood, so no blinding lights late at night. And it's 200 lumens, which is totally fine. It has high, medium, and low. If you want to know more about it, just google "zebralight h51" and click on the zebralight site link. On the site it's only $64. But there are cheaper headlights of course. I got one of those $8 ones off of ebay. Shipping took like 3 weeks, but it's a great light. I'd say it's only around 100ish lumen, but it's never broke and and has a flood to throw. Takes 3 aaa's but on high those last 1.5 hours, I've already had more than that and they are still burning. The light has a high, med, and high strobe. These are gone threw by a clicky. It's one click: high, another click: low, another click: strobe, another click: off. I kinda like this light because of the amount of lumens. When you have really night adjusted eyes, the around 30 lumens low does perfect, does hurt your eyes, even if you just woke up in the middle of the night. Although it wasn't designed to like the zebralight, you can detach the light from the straps, takes 2 seconds. Then you just have the battery housing and the light w/reflector. I actually bought another of these for a friend and he likes em too.
Edit: just realized those were hyperlinks...fail. Don't see why you'd have 7 crees, I would rather just have one, those are going to be very underdriven. Just for looks I guess. But, I would definately get the headlamp. I'm all for a good deal, but I HIGHLY doubt that penlight will survive even one drop on pavement.