I agree with everyone.
I hate bow ties (some people pull it off), so throw that out if it was an option. Use a tie and see what works for you. If you're a slim guy, get a slim fitted tie, but if you're a bit big, get a regular one. Make sure it's simple... black! As for the knot, it depends on your body type. If you're on a budget, get a tie from Zara, but if you got money to blow, hit up any of the luxury dept. stores like Barneys or Saks.
Shirts... I'd opt for a white french cuff shirt and a nice pair of cuff links. If you're on a budget, get the shirt from Zara and maybe even the links. If you have money, I like the cuff links at Burberry and Ascot Chang makes the best shirts.
As for the suit... I'd get black for a wedding. Make sure you choose the correct fit. Good suits aren't cheap and your going to have it for awhile. Make sure it's got 3 buttons too. Zara again... cheap, but good. Also J.Crew makes nice suits too. For ballers, Armani's the best, but I like BOSS.
Also, I'd do a hangkercheif and fold it into a pocket square and place it in my chest pocket. Get a cheap pack at Macy's lol. Poor or rich.
As for shoes, shop Aldo if you're broke. If you can afford it, I highly recommend Salvatore Ferragamo.
Belts... Salvatore Ferragamo FTW! If you're on a budget... figure it out haha.