I am trying to buy a suit for a business Conference. what is the best type of suit to buy. and is it ok to wear a vested suit.

I have to wear a suit to the FBLA conference next month, which is a regional business club conference. What should I wear? I don’t want to be super conservative but definitely want to look sleek and polished, without exposing anything unnecessary. I’m having trouble finding good suits and stuff to wear underneath, and shoes too. Links please! Thank you!

I’m 15, 105 pounds, and 5′3″ if that helps.

I’m heading to China next week for a business conference and am desperately looking for a conservative suit to wear whilst in the scorching heat – any ideas on where to look? I’m in London and all I can find are heavy woollen suits!

Thanks!
Sorry I should have mentioned I’m looking for ladies suits!