It looks like you decided to go with Tara (good choice). Playing Resurrectionists tends to be a cumulative process. You start with someone like Seamus, who doesn't summon much, but comes with the useful Rotten Belles (Hanged, Yin, and Dead Doxies are the boxes you hire to support him), then you grab McMourning, who summons a bit more (grab a box of Canine Remains and at least one more Flesh Construct).
You might want to grab Yan Lo at this point. He's not much of a summoner, but Chiaki is the goto model for condition removal in Resurrectionists, and if you get Toshiro and Izamu you'll have all the ancestors he can resummon. He's a very different style of play to your usual Masters.
The three summoners are next, and I would get them in the order Molly, Nicodem, and Kirai. Molly and Nico can summon from the same pool of models. Kirai only really comes with summons, so she's not a good box to start with, and then you have to buy Datsue Ba anyway.
Tara would be my next choice (although playing Outcasts she's really my first filthy Resur). Her crew box only benefits her in Resurs, but she again has a different style of play.
Reva would be the final master I bought. She's a long range nuker in the style of Sonnia or Rasputina, which is something new for Resurrectionists, but she is also, perhaps, a bit strong.
Since more than half of Resurrectionist masters are summoners, three of which have very large pools of models, you will need to buy a bunch of extra models to bring to the table. That said, you don't need all of them. Guild Autopsies are a good summon that gives you a shooting model (rare in Resurs) that also hands out poison (good for McMourning). Punk Zombies are great melee units, and come with Nicodem. If you're running Kirai you'll need some additional spirits as she can't summon Horrors. The Rogue Necromancy is a bit of a beater and can be summoned with the Spare Parts upgrade that any Master can take.
https://pullmyfinger.wikispaces.com/M2E+Resurrectionists
