The Horseware Amigo rugs offer a very good fit and quality for a relatively low price. The Amigo Hero 6 rugs are made of 600D polyester and the Amigo Bravo 12 blankets are made of 1200D polyester and have additional features such as attachment points for a neck and liner (under rug). In addition, there are special variants available such as the XL rugs for wide horses and Amigo Plus rugs which come with a removable neck.
There are many horse rugs which have the option of attaching a loose rug neck. Rug necks come in different fill types, for example between 0g and 250g.