10 bps arent that much harder to care for than 1 imo...
Just some extra time cleaning/feeding and more money obviously but still quite managable.

You have 1 male mojave now so i would reccomend one of your females be a butter or lesser. Or like a pastel butter or pastel lesser so that way you can produce BELs. Also id get a hypo female, pin het hypo, and pastel hypo or het hypo. Then for a males just get 1 more. Whatever you get just make sure its hypo. Like pastel hypo.
Then you'll have 2.4 snakes and be well on your way to producing some nice snakes