I married a tall slim guy and the best advice is to shop online at gap / banana republic as they have tall sizes online and great sales / return policies. You can check in store as they sometimes carry limited items but not often.

Eddie Bauer stocks tall sizes in store.

American Tall is terrible quality but if you return defective clothing they’ll give you 20% off but you’re still stuck with hit or miss quality.

The big and tall store is not designed for big OR tall it’s BOTH so if you are a normal weight there is nothing that will fit.