Both electroless nickel and electrolytic nickel require a base coat of copper. Copper can also be plated electroless-ly.
While it is alleged that electrolytic plating looks better (i.e., bright/shiny) than electroless, that’s not always true. A lot of electroless nickel ends up on plastic (salt shaker lids, for instance). However, if you’re doing nickel plating for appearance, then an absolutely pristine clean and good substrate surface finish are crucial.
Each process has pros/cons but unless you have technical requirements for corrosion resistance, lubricity, ductility, etc. then you can probably choose either one. And frankly, if you have technical requirements for corrosion resistance or whatever then you probably shouldn’t consider doing it yourself at DMS anyway.