There are some meter styles with a thinner needle that you can change. I'm not sure how thin you need the meter needle to be, but you can create your own meter style class. The attached class with draw a really thin (1 pixel wide) needle.
To use this class, you would add the following for you meter in the forms load or constructor
meter1.MeterStyle = new CustomNeedle();
You can do similar customization for the slide as well.
This is described in the help topic "Extending the Measurement Studio Numeric Pointer .NET controls"
I hope this helps
Bilal Durrani
NI