As long as the light is coherent when it hits the slits, any set up should be fine.
A good experiment to try if you have a photomultiplier is to enclose the experiment so no light can get in. Attenuate the laser until only one photon is present in the box at anyone time (on average). Scan the photomultiplier across the interferance pattern and show that it matches the pattern that would be expected for a macroscopic wave traveling through the slits.
It is a simple illustration of the quantum behaviour of light.
Claude.