The black sex link is generally made by putting a production red rooster over hatchery type Barred Rock hens. Generally, these are both good laying strains of hatchery stock. Any good layer strain now used over your Black Sex Links will also produce good layers.
Since the BSL is a hybrid, breeding something over them is producing more hybrids/mixes/mutts. If you want them barred, put a Barred Rock cock bird over them. All the chicks would likely be barred and good layers.