Unless you're using continuous lighting then your in camera metering will be no use anyway.
As soon as you're into studio flash set your fastest sync speed, the aperture to give the desired effect and adjust the lights to suit you. You don't want to be adjusting your camera to suit the lighting IMO.
Andrew is right, a light meter would help but you can also get away with chimping the screen and the histogram.
Studio situations often fool the in-camera meter.
But don't worry about it, be guided by the LCD - histogram with blinkies enables (highlight over exposure warning, in the menu). It's more accurate than any metering method anyway. Manual is best, and as the light should be constant, then the exposure won't change once it's set.
Use evaluative to get you somewhere close, then adjust the shutter speed/aperture/ISO until it's just right.
Hoppy I don't want to go down the wole road of exposure but without understanding what the OP is trying to shoot,m using the histogram is not always the best. Shooting a dark subject with a dark background I'd say to get blinkies you'd be using a lot more light to get the blinkies -
I understand your point and agree to a degree but it doesn't always make it the best way - unless you fully understand the histogram.
If your using manual then the metering mode won't affect the photo, it will only affect the indication on the scale (probably telling you it's going to be under exposed, but that's because it's stupid).