It may look and feel artificial on your wedding day. A very good nail strengthener is Nailtiques. It works wonders. Formula 2, of course. One coat per day for two weeks and your nails will be gorgeous.
Highlights look best within the first month and a half of coloring.
I suggest getting your highlights done three weeks before your wedding date. That way if any adjustments need to be made, i.e. lighter or darker, there is plenty of time to do it. Colors are tailored to individual hair color, eye color, and occasionally, a makeup trend. Since trends and skin, depending on tanning and time of year, can occasionally change, it's best to try a few looks out, take someone with you, and ask which one is the most flattering for you. This will ensure that the lip and cheek tones are similar.