I would recomend Euonymus fortunei 'Coloratus' (Wintercreeper). It is a broadleaf evergreen, and grows to about 18" tall. It works well on slopes because it's stems root to the ground wherever they touch.

Heather is a possible. Prostrate junipers. If it's hardy in your area, Phormium cookianum varieties. Cortaderia selloana, but it can be a bit scruffy in some seasons. It is also a curse in a plantation forestry area, but very effective.