Don't bother trying to get too clever here. A dark blue / navy suit, white shirt and wedding tie are unimpeachable. You may not 'stand out' in a garish, attention-seeking way but that's not your job as a wedding guest. You will certainly get noticed in a more subtle way if your togs are well fitted. I wouldn't bother with the waistcoat.
Either of these shirts would be fine IMO. They are both appropriate for a tuxedo so go with the one that fits you best or feels most comfortable. Hope you have some nice formal studs and cuff links to go with.
No love for regatta blazers J?Good luck with the venture. As you can see I don't even know how to get an avatar so would be less than useless to you, but applaud your efforts to edumacate us with illustrations. Please keep persevering.