Sekonic L-358 Flash Meter and Ambient Light Meter
I'd get one here, or if I wanted one with the chip that works with the PocketWizards then I'd get this one here. I got just the PocketWizard add-on chip here.
This is a hand-held lightmeter that you can use with studio lights to both set your camera properly and to setup the lights to create the balance you desire. You can also use it outside of the studio to measure light in unique situations.
With the digital age, this second use isn't as important since you get instant feedback from your digital camera and with the use of your camera's built in histogram you can get a lot more information about the scene than you can from the meter.
Measurements: f/1.0 to f/90.9 for both incident and reflect light readings. This is displayed in full, 1/2, or 1/3 steps.
Repeatability: +/-0.1EV or less - this is a good rating.
ISO Range: 3 to 8000 in 1/3 steps. I sure hope that this covers the film and digital range you have available to you!
Ambient Light Shutter Speed Range: 30 minutes to 1/8000sec shown in full, 1/2, or 1/3 steps.
Strobe Shutter Speed Range: 30 minutes to 1/1000 sec shown in full, 1/2, or 1/3 steps. You'll want to just use something like 1/125sec here.
Cine Speeds: 2 - 360 frames per second (yes, this can do movie speed configurations as well).
Power: CR123A battery (available at the camera store and at most larger grocery stores and pharmacies).
Add-Ons: You can add a module (seen on the right) capable of firing your PocketWizard-enabled strobes with just the push of a button.
Extras: This flash can measure a studio strobe light and compare this to the ambient light and tell you the total amount of the exposure that comes from ambient light (show in 10% increments).
It works great. I have no complaints about this unit.
The only issue I've ever had was when I first got my module to work with the PockeWizard system. I inserted it but it didn't seem to work. I ended up power cycling the light meter twice and then it started working and hasn't failed since.
Assuming you're thinking of using something like this for your studio lights, here's how to use it.
I bought just the light meter first and then invested in the PocketWizard setup. If you have the money to start off with the PWs then I encourage you to do so. But, if you can't afford it, then it isn't a big deal to spend $50 for the add-on chip later.
Basically, no way is a lot better or cheaper than the other. The only recommendation I can really make is that you will more than likely end up going to the PWs at some point. They aren't cheap, in fact I think they are too expensive for what they do, but it is sort of inevitable. If you're on the fence and can afford to, just do it and don't look back.