HorseHopes on Etsy has great stuff!
Look at etsy! They have great stuff!
Elbow grease ;) But, you should know, you can't get dirt off and shine on with one brush and one step. You must first remove all dirt with a stiffer brush, then go back with a finishing brush to add shine :)
The brush brand I really like is Oster. They make a really good selection of grooming supplies all the way to clippers :)