SEE or Kylo will both be fine for ds Geo tb. With see you get imp troopers, empire (yes ep lead with Vader, tarkin, thrawn, and royal guard will work in most phases), and a Sith team under see.
Kylo will give you a first order team under slkr and probably a 2nd that can be used in a pinch.
Jml or Rey will do similar things for ls geo. Though I think you get higher quality teams for jml but he takes longer.
See will give you empire, with, and imp troopers for assualt battles.
Slkr will solo hstr (though if they make it simable, that won't help much).
Jml gives you jedi and rebels for assualt battles.
I like the gear from assualt battles more than soloing hstr. You can usually get a ns jka team in p3 and still get top 10 so the extra from a solo isn't all that much.
So I would recommend See and jml depending on whether you want to focus on ds or ls first. If hstr is a big concern, then maybe go for jmk as soon as you have wat close enough.