My suggestion, and I hope my gay license doesn't get revoked for this, look at fashion websites and magazines. Look for styles and looks where you see yourself. You will make the right choice if you trust your taste and common sense (yes, people, common sense exists).
Also, you can still look sloppy in the best outfit if you don't take care of the details. Make sure it fits well, it's clean, neat, ironed and new (or newish). Everything in its place. No too long/short sleeves, not too wide for you pants, hem at the right length. The outfit itself is only one part of the equation. I don't think I have to tell you to shave and shower properly too, but I just did.
Of course, consider that it's your wedding, that you want to look sharp, and that most of the beauty will be focused on the bride.
Good luck.