You are the groom? What does your fiancee suggest? Navy or charcoal seem to dark for a May FL wedding on a yacht. I would consider lighter colors (off-white, light blue, dove gray, etc.) to be more appropriate for the occasion.
As a rider and commuter, I would not wear wool dress pants on a bike if I had to look good when I arrived at the office (especially in Portland weather). Get all-weather bike pants (or full riding suit) and change when you get to the office.
Breitling chronograph to IWC portofino is a wide range in style. Best bang for the buck brands include: Tissot, Oris, Hamilton, Seiko, Sinn, Baume Mercier, Tutima. I suggest trying on as many as you can and find one you like. Buying sight unseen is not a good idea unless you know exactly what you want.
Get MTM trousers. Keep in mind, trouser legs need to give you enough material in the thighs so you don't split them when you sit. The legs should taper slightly from the thickest thigh area to your ankles. Too much taper with throw the proportion off. No one can see how skinny your calves are under the fabric.
I would definitely go custom rather than OTR. My preference would be midnight blue, double breasted, peak lapel no vent. A DB tux eliminates the need for a vest or cummerbund. In addition to looking great as a tux, it can play double duty as a more formal suit for other occasions with a long tie (instead of a bow tie). Just my preference.