What size cans are you installing? What wattage of bulb are you intending to use in the can? Varying these could have very different affects. A larger number of smaller cans with lower wattage bulbs, say 4 in, might distribute light more evenly. Where fewer 6 in cans may have more of a focus affect.

8 wouldn't be overkill if they are on a dimmer switch.

I agree, I don't think 8 is out of line, especially if you go with 4".

Thanks I don't know why he thinks I need fewer maybe because the kitchen is not very wide !