Everyone has their personal preference for shampoos and conditioners
here are a few that I like:

Crown Royale  (I use formula #1 for silky coats - not #3 that they have listed for Wheatens - that's for fluffy coats)
Mr. Christal's
The Coat Handler (I like the leave in conditioner, but I don't like the shampoo as well)

• I use Treseme' oil treatments occasionally (human product). 
• To help add volume to fine, limp leg furnishings I use Mane n Tail shampoo by Straight Arrow (horse product).
• I dilute infusium leave in conditioner (human product) with a small amount of water and mist into coat for everyday combing and when needed to help control static.
• I always finish off with a light mist of Crown Royale Magic Touch grooming spray.

A few links for supplies:

J-B Wholesale
Cherrybrook
Drs. Foster and Smith