The simplest way to look at what i want from potential relationships right at the moment is to say that nothing has changed. I'm interested in the exact same thing i was interested in six months ago, cute geeky girls who're okay with being the secondary in a poly relationship. As far as the impact it has on any third parties, the fact that my my primary is a dead girl is just a minor, incredibly awkward to explain detail, right? =P
"Before we get involved i just want to make sure you understand my relationship with my primary comes first and i don't want you trying to interfere with that. But don't worry, she won't be taking up too much of my time, because she's dead."
Yes, that should go over well.