The 3mm is perfect with your solitaire or on its own, in my opinion. It will always be a classic. You can always do a stackable, varied combo later for the right hand (like in pic #8 above) if you choose to, or add another band to the set on your left hand (like in pic #7 above) for an anniversary down the line. In my experience, once you choose your band, you will likely not change up your wedding set on a regular basis but will wear the 2 rings together 99% of the time.