Advice for Premium Retailers/Auction Houses

I am slowly ramping up my collecting and have the intention of starting a deeper cellar and investing ~$100k in a collection in the near future. I realize this might not be a question for everyone, but does anyone have any retailer or auction houses that they love working with? Maybe someone you work with already that I could be referred to? I am based in Los Angeles, but am open to working with the best if they are not CA based. I am looking to buy from both auction and retail.

Emphasis on classics, but always love to hear recommendations from someone. Thanks all!!